Titulaire de la chaire CRSNG en efficacité énergétique à l’Université de Sherbrooke (2014-19)
Editorial board : "Journal of Nonlinear Dynamics", "Progress in Computational Fluid Dynamics", "American Journal of Fluid Mechanics", the "Scientific World Journal"
Activités
Ecoulements en rotation: Taylor-Couette, rotor-stator, Von Karman…
Problèmes de refroidissement de machines électriques par jet impactant…
Production, stockage et transport de froid par coulis de glace
Modélisation numérique des éjecteurs mono et diphasiques
Modélisation d’un régénérateur poreux en réfrigération magnétique
Transport de mucus dans le système respiratoire humain
Publications scientifiques au M2P2
2019
Sylvain Chateau, Julien Favier, Sébastien Poncet, Umberto d'Ortona. Why antiplectic metachronal cilia waves are optimal to transport bronchial mucus. Physical Review E , 2019, 100 (4), pp.042405. ⟨10.1103/PhysRevE.100.042405⟩. ⟨hal-02468006⟩ Plus de détails...
The coordinated beating of epithelial cilia in human lungs is a fascinating problem from the hydrodynamics perspective. The phase lag between neighboring cilia is able to generate collective cilia motions, known as metachronal waves. Different kinds of waves can occur, antiplectic or symplectic, depending on the direction of the wave with respect to the flow direction. It is shown here, using a coupled lattice Boltzmann-immersed boundary solver, that the key mechanism responsible for their transport efficiency is a blowing-suction effect that displaces the interface between the periciliary liquid and the mucus phase. The contribution of this mechanism on the average flow generated by the cilia is compared to the contribution of the lubrication effect. The results reveal that the interface displacement is the main mechanism responsible for the better efficiency of antiplectic metachronal waves over symplectic ones to transport bronchial mucus. The conclusions drawn here can be extended to any two-layer fluid configuration having different viscosities, and put into motion by cilia-shaped or comb-plate structures, having a back-and-forth motion with phase lags.
Sylvain Chateau, Julien Favier, Sébastien Poncet, Umberto d'Ortona. Why antiplectic metachronal cilia waves are optimal to transport bronchial mucus. Physical Review E , 2019, 100 (4), pp.042405. ⟨10.1103/PhysRevE.100.042405⟩. ⟨hal-02468006⟩
Mohamad Cheayb, Mylène Marin Gallego, Mohand Tazerout, Sébastien Poncet. Modelling and experimental validation of a small-scale trigenerative compressed air energy storage system. Applied Energy, 2019, 239, pp.1371-1384. ⟨10.1016/j.apenergy.2019.01.222⟩. ⟨hal-02384256⟩ Plus de détails...
• A thermodynamic model of a simple trigenerative-CAES is developed. • The model is validated experimentally. • The performances of the simple configuration are assessed. • Technological issues on the trigenerative CAES are highlighted. New advances in compressed air energy storage systems have been recently made especially regarding the use of heat generated from compression. On this basis, the concept of the trigenerative compressed air energy storage (T-CAES) has recently been proposed. Many studies highlighted the feasibility and the benefits of this system to be placed close to the energy demand. The aim of this study is to examine a simple configuration of this system by a coupled experimental/mod-elling approach. This paper presents a detailed thermodynamic model of both the main components and the whole system. An experimental bench is used to validate the model and to investigate the effect of the operating parameters on the system efficiency and the model accuracy. The model predictions are consistent with the experimental measurements during the charge, storage and discharge phases. It has been found that the temperature drop across the pressure regulator should not be ignored and is governed by the Joule-Thomson effect. Besides, it has been observed that the input temperature of the air motor must be accounted for in the assessment of future improved configurations. It was noted that the system efficiency increases significantly by adding the cooling and heating potentials. However, the round trip efficiency remains low at 15.6%. Output values of the model are in good agreement with the experimental results with an error less than 13.2%. The model can be applied as a basis for the performance assessment of prospective configurations and improvements of trigenerative compressed air energy storage.
Mohamad Cheayb, Mylène Marin Gallego, Mohand Tazerout, Sébastien Poncet. Modelling and experimental validation of a small-scale trigenerative compressed air energy storage system. Applied Energy, 2019, 239, pp.1371-1384. ⟨10.1016/j.apenergy.2019.01.222⟩. ⟨hal-02384256⟩
Mohamad Cheayb, Sébastien Poncet, Mylène Marin Gallego, Mohand Tazerout. Parametric Optimisation of a Trigenerative Small Scale Compressed Air Energy Storage System †. Proceedings, MDPI, 2019, 23, ⟨10.3390/proceedings2019023005⟩. ⟨hal-02384277⟩ Plus de détails...
Recently, major improvement on compressed air energy storage technology has been made by using the heat of compression for heating energy or using it to preheat the compressed air in the expansion phase and by demonstrating its ability to produce cooling energy. Thus, the trigenerative compressed air energy storage has been introduced. In this paper, we introduce a configuration of trigenerative compressed air energy storage system giving the preference to the electric energy production. The study then focuses on undertaking an optimization study via a parametric analysis considering the mutual effects of parameters. This analysis is applied to a micro-scale application including the existing technological aspects. The parametric study results applied on the hot temperature of the thermal energy storage indicate the possibility to find an optimal solution as a trade-off between system performances and other parameters reflecting its cost. On the contrary, the selection of the maximal storage pressure cannot be achieved by finding a compromise between energy density and system efficiency. A complete study of other design parameters will be addressed in a future publication.
Mohamad Cheayb, Sébastien Poncet, Mylène Marin Gallego, Mohand Tazerout. Parametric Optimisation of a Trigenerative Small Scale Compressed Air Energy Storage System †. Proceedings, MDPI, 2019, 23, ⟨10.3390/proceedings2019023005⟩. ⟨hal-02384277⟩
Sylvain Chateau, Umberto d'Ortona, Sébastien Poncet, Julien Favier. Transport and Mixing Induced by Beating Cilia in Human Airways. Frontiers in Physiology, 2018, 9, pp.161. ⟨10.3389/fphys.2018.00161⟩. ⟨hal-01875672⟩ Plus de détails...
The fluid transport and mixing induced by beating cilia, present in the bronchial airways, are studied using a coupled lattice Boltzmann-Immersed Boundary solver. This solver allows the simulation of both single and multi-component fluid flows around moving solid boundaries. The cilia aremodeled by a set of Lagrangian points, and Immersed Boundary forces are computed onto these points in order to ensure the no-slip velocity conditions between the cilia and the fluids. The cilia are immersed in a two-layer environment: the periciliary layer (PCL) and the mucus above it. The motion of the cilia is prescribed, as well as the phase lag between two cilia in order to obtain a typical collective motion of cilia, known as metachronal waves. The results obtained from a parametric study show that antiplectic metachronal waves are the most efficient regarding the fluid transport. A specific value of phase lag, which generates the larger mucus transport, is identified. The mixing is studied using several populations of tracers initially seeded into the pericilary liquid, in the mucus just above the PCL-mucus interface, and in the mucus far away from the interface. We observe that each zone exhibits different chaotic mixing properties. The larger mixing is obtained in the PCL layer where only a few beating cycles of the cilia are required to obtain a full mixing, while above the interface, the mixing is weaker and takes more time. Almost no mixing is observed within the mucus, and almost all the tracers do not penetrate the PCL layer. Lyapunov exponents are also computed for specific locations to assess how the mixing is performed locally. Two time scales are introduced to allow a comparison between mixing induced by fluid advection and by molecular diffusion. These results are relevant in the context of respiratory flows to investigate the transport of drugs for patients suffering from chronic respiratory diseases.
Sylvain Chateau, Umberto d'Ortona, Sébastien Poncet, Julien Favier. Transport and Mixing Induced by Beating Cilia in Human Airways. Frontiers in Physiology, 2018, 9, pp.161. ⟨10.3389/fphys.2018.00161⟩. ⟨hal-01875672⟩
Olivier Lafforgue, Isabelle Seyssiecq, Sébastien Poncet, Julien Favier. Rheological properties of synthetic mucus for airway clearance. Journal of Biomedical Materials Research Part A, 2018, 106 (2), pp.386 - 396. ⟨10.1002/jbm.a.36251⟩. ⟨hal-01678912⟩ Plus de détails...
In this work, a complete rheological characterization of bronchial mucus simulants based on the composition proposed by Zahm et al. [1] is presented. Dynamic Small Amplitude Oscillatory Shear (SAOS) experiments, Steady State (SS) flow measurements and three Intervals Thixotropy Tests (3ITT), are carried out to investigate the global rheological complexities of simulants (viscoelasticity, viscoplasticity, shear-thinning and thixotropy) as a function of scleroglucan concentrations (0.5 to 2wt%) and under temperatures of 20 and 37 °C. SAOS measurements show that the limit of the linear viscoelastic range as well as the elasticity both increase with increasing sclerogucan concentrations. Depending on the sollicitation frequency, the 0.5wt% gel response is either liquid-like or solid-like, whereas more concentrated gels show a solid-like response over the whole frequency range. The temperature dependence of gels response is negligible in the 20-37°C range. The Herschel-Bulkley (HB) model is chosen to fit the SS flow curve of simulants. The evolution of HB parameters versus polymer concentration show that both shear-thinning and viscoplasticity increase with increasing concentrations. 3ITTs allow calculation of recovery thixotropic times after shearings at 100s-1 or 1.6s-1. Empiric correlations are proposed to quantify the effect of polymer concentration on rheological parameters of mucus simulants.
Olivier Lafforgue, Isabelle Seyssiecq, Sébastien Poncet, Julien Favier. Rheological properties of synthetic mucus for airway clearance. Journal of Biomedical Materials Research Part A, 2018, 106 (2), pp.386 - 396. ⟨10.1002/jbm.a.36251⟩. ⟨hal-01678912⟩
Journal: Journal of Biomedical Materials Research Part A
Olivier Lafforgue, N. Bouguerra, Sebastien Poncet, Isabelle Seyssiecq, Julien Favier, et al.. Thermo-physical properties of synthetic mucus for the study of airway clearance. Journal of Biomedical Materials Research Part A, 2017, 105 (11), pp.3025-3033 ⟨10.1002/jbm.a.36161⟩. ⟨hal-01596484⟩ Plus de détails...
In this article, dynamic viscosity, surface tension, density, heat capacity and thermal conductivity, of a bronchial mucus simulant proposed by Zahm et al., Eur Respir J 1991; 4: 311–315 were experiementally determined. This simulant is mainly composed of a galactomannan gum and a scleroglucan. It was shown that thermophysical properties of synthetic mucus are dependant of scleroglucan concentrations. More importantly and for some scleroglucan concentrations, the syntetic mucus, exhibits, somehow, comparable thermophysical properties to real bronchial mucus. An insight on the microstructure of this simulant is proposed and the different properties enounced previously have been measured for various scleroglucan concentrations and over a certain range of operating temperatures. This synthetic mucus is found to mimic well the rheological behavior and the surface tension of real mucus for different pathologies. Density and thermal properties have been measured for the first time.
Olivier Lafforgue, N. Bouguerra, Sebastien Poncet, Isabelle Seyssiecq, Julien Favier, et al.. Thermo-physical properties of synthetic mucus for the study of airway clearance. Journal of Biomedical Materials Research Part A, 2017, 105 (11), pp.3025-3033 ⟨10.1002/jbm.a.36161⟩. ⟨hal-01596484⟩
Journal: Journal of Biomedical Materials Research Part A
Sylvain Chateau, Julien Favier, Umberto D’ortona, Sebastien Poncet. Transport efficiency of metachronal waves in 3D cilium arrays immersed in a two-phase flow. Journal of Fluid Mechanics, 2017, 824, pp.931 - 961. ⟨10.1017/jfm.2017.352⟩. ⟨hal-01592834⟩ Plus de détails...
This work reports the formation and characterization of antipleptic and symplectic metachronal waves in 3D cilium arrays immersed in a two-fluid environment, with a viscosity ratio of 20. A coupled lattice Boltzmann-immersed-boundary solver is used. The periciliary layer is confined between the epithelial surface and the mucus. Its thickness is chosen such that the tips of the cilia can penetrate the mucus. A purely hydrodynamical feedback of the fluid is taken into account and a coupling parameter alpha is introduced, which allows tuning of both the direction of the wave propagation and the strength of the fluid feedback. A comparative study of both antipleptic and symplectic waves, mapping a cilium interspacing ranging from 1.67 up to 5 cilium lengths, is performed by imposing metachrony. Antipleptic waves are found to systematically outperform symplectic waves. They are shown to be more efficient for transporting and mixing the fluids, while spending less energy than symplectic, random or synchronized motions.
Sylvain Chateau, Julien Favier, Umberto D’ortona, Sebastien Poncet. Transport efficiency of metachronal waves in 3D cilium arrays immersed in a two-phase flow. Journal of Fluid Mechanics, 2017, 824, pp.931 - 961. ⟨10.1017/jfm.2017.352⟩. ⟨hal-01592834⟩
Romain Oguic, Sébastien Poncet, Stéphane Viazzo. High-order direct numerical simulations of a turbulent round impinging jet onto a rotating heated disk in a highly confined cavity. International Journal of Heat and Fluid Flow, 2016, 61 (B), pp.366-378. ⟨10.1016/j.ijheatfluidflow.2016.05.013⟩. ⟨hal-01461786⟩ Plus de détails...
The present work reports Direct Numerical Simulations (DNS) of an impinging round jet onto a rotating heated disk in a confined rotor-stator cavity. The geometrical characteristics of the system correspond to the experimental set-up developed by u. Pelle and S. Harmand. Heat transfer study in a rotor-stator system air-gap with an axial inflow. Applied Thermal Engineering, 29:1532-1543, 2009.]. The aspect ratio of the cavity G = h/R-d between the interdisk spacing h and the rotor radius R-d is fixed to 0.02 corresponding to a narrow-gap cavity. The axial Reynolds number Red based on the jet characteristics is also fixed to Re-j = 5300, while the rotational Reynolds number Re-Omega may vary to preserve the swirl parameter N proportional to Re(Omega)dRe(j) (0 <= N <= 2.47) between the present simulations and the experimental data of [J. Pelle and S. Harmand. Heat transfer study in a rotor-stator system air-gap with an axial inflow. Applied Thermal Engineering, 29:1532-1543, 2009.] and [T. D. Nguyen, J. Pelle, S. Harmand, and S. Poncet. PIV measurements of an air jet impinging on an open rotor-stator system. Experiments in Fluids, 53:401-412, 2012.] for comparisons. The results are discussed in terms of radial distributions of the mean velocity components and corresponding Reynolds stress tensor components. The swirl parameter does not modify the size of the recirculation bubble developed along the stator close to the pipe exit. For N >= 1.237, centrifugal effects at the rotor periphery are balanced by a centripetal flow along the stator. Some spiral patterns develop then in the stator boundary layer corresponding to the SRIII instability of [L. Schouveiler, P. Le Gal, and M. P. Chauve. Instabilities of the flow between a rotating and a stationary disk. Journal of Fluid Mechanics, 443:329-350, 2001.] in an enclosed cavity. The numerical results are found to agree particularly well with the experimental data in terms of the distribution of the local Nusselt number along the rotor. Finally, a correlation for its averaged value is proposed according to the swirl parameter. (C) 2016 Elsevier Inc. All rights reserved.
Romain Oguic, Sébastien Poncet, Stéphane Viazzo. High-order direct numerical simulations of a turbulent round impinging jet onto a rotating heated disk in a highly confined cavity. International Journal of Heat and Fluid Flow, 2016, 61 (B), pp.366-378. ⟨10.1016/j.ijheatfluidflow.2016.05.013⟩. ⟨hal-01461786⟩
Journal: International Journal of Heat and Fluid Flow
Sergio Croquer, Sébastien Poncet, Zine Aidoun. Turbulence modeling of a single-phase R134a supersonic ejector. Part 1: Numerical benchmark. International Journal of Refrigeration, 2016, 61 (8), pp.140-152. ⟨10.1016/j.ijrefrig.2015.07.030⟩. ⟨hal-01300110⟩ Plus de détails...
The present work reports a numerical analysis of a supersonic ejector in single-phase conditions using R134a as the working fluid. A numerical benchmark of some thermodynamic and two-equation turbulence models has been carried out to highlight the numerical model offering the best compromise between accuracy and calculation cost. The validation is achieved by comparing the predicted entrainment ratio with the experimental data of Garcia del Valle et al. (2014). The k−ω SST model together with the REFPROP 7.0 database equation appears to be the best combination to predict accurately the ejector performance and capture the shock wave structure. The influence of the outlet temperature, the discussion about the validity of some assumptions made by one-dimensional (1D) models and the exergy analysis within the ejector for the present operating conditions will later be discussed in Part 2 (Croquer et al., 2015).
Sergio Croquer, Sébastien Poncet, Zine Aidoun. Turbulence modeling of a single-phase R134a supersonic ejector. Part 1: Numerical benchmark. International Journal of Refrigeration, 2016, 61 (8), pp.140-152. ⟨10.1016/j.ijrefrig.2015.07.030⟩. ⟨hal-01300110⟩
S. Croquer, S. Poncet, Z. Aidoun. Turbulence modeling of a single-phase R134a supersonic ejector. Part 1: Numerical benchmark. International Journal of Refrigeration, 2016, 61 (8), pp.140-152. ⟨10.1016/j.ijrefrig.2015.07.030⟩. ⟨hal-01300110⟩ Plus de détails...
The present work reports a numerical analysis of a supersonic ejector in single-phase conditions using R134a as the working fluid. A numerical benchmark of some thermodynamic and two-equation turbulence models has been carried out to highlight the numerical model offering the best compromise between accuracy and calculation cost. The validation is achieved by comparing the predicted entrainment ratio with the experimental data of Garcia del Valle et al. (2014). The k−ω SST model together with the REFPROP 7.0 database equation appears to be the best combination to predict accurately the ejector performance and capture the shock wave structure. The influence of the outlet temperature, the discussion about the validity of some assumptions made by one-dimensional (1D) models and the exergy analysis within the ejector for the present operating conditions will later be discussed in Part 2 (Croquer et al., 2015).
S. Croquer, S. Poncet, Z. Aidoun. Turbulence modeling of a single-phase R134a supersonic ejector. Part 1: Numerical benchmark. International Journal of Refrigeration, 2016, 61 (8), pp.140-152. ⟨10.1016/j.ijrefrig.2015.07.030⟩. ⟨hal-01300110⟩
Zhe Li, Julien Favier, Umberto D 'Ortona, Sébastien Poncet. An immersed boundary-lattice Boltzmann method for single- and multi-component fluid flows. Journal of Computational Physics, 2016, 304, pp.424-440. ⟨10.1016/j.jcp.2015.10.026⟩. ⟨hal-01225681⟩ Plus de détails...
The paper presents a numerical method to simulate single-and multi-component fluid flows around moving/deformable solid boundaries, based on the coupling of Immersed Boundary (IB) and Lattice Boltzmann (LB) methods. The fluid domain is simulated with LB method using the single relaxation time BGK model, in which an interparticle potential model is applied for multi-component fluid flows. The IB-related force is directly calculated with the interpolated definition of the fluid macroscopic velocity on the Lagrangian points that define the immersed solid boundary. The present IB-LB method can better ensure the no-slip solid boundary condition, thanks to an improved spreading operator. The proposed method is validated through several 2D/3D single-and multi-component fluid test cases with a particular emphasis on wetting conditions on solid wall. Finally, a 3D two-fluid application case is given to show the feasibility of modeling the fluid transport via a cluster of beating cilia.
Zhe Li, Julien Favier, Umberto D 'Ortona, Sébastien Poncet. An immersed boundary-lattice Boltzmann method for single- and multi-component fluid flows. Journal of Computational Physics, 2016, 304, pp.424-440. ⟨10.1016/j.jcp.2015.10.026⟩. ⟨hal-01225681⟩
Romain Oguic, Stéphane Viazzo, Sébastien Poncet. A parallelized multidomain compact solver for incompressible turbulent flows in cylindrical geometries. Journal of Computational Physics, 2015, 300, pp.710-731. ⟨10.1016/j.jcp.2015.08.003⟩. ⟨hal-01299082⟩ Plus de détails...
We present an efficient parallelized multidomain algorithm for solving the 3D Navier–Stokes equations in cylindrical geometries. The numerical method is based on fourth-order compact schemes in the two non-homogeneous directions and Fourier series expansion in the azimuthal direction. The temporal scheme is a second-order semi-implicit projection scheme leading to the solution of five Helmholtz/Poisson equations. To handle the singularity appearing at the axis in cylindrical coordinates, while being able to have a thinner or conversely a coarser mesh in this zone, parity conditions are imposed at r=0r=0 for each flow variable and azimuthal Fourier mode. To simulate flows in irregularly shaped cylindrical geometries and benefit from a hybrid OpenMP/MPI parallelization, an accurate perfectly free-divergence multidomain method based on the influence matrix technique is proposed. First, the accuracy of the present solver is checked by comparison with analytical solutions and the scalability is then evaluated. Simulations using the present code are then compared to reliable experimental and numerical results of the literature showing good quantitative agreements in the cases of the axisymmetric and 3D unsteady vortex breakdowns in a cylinder and turbulent pipe flow. Finally to show the capability of the algorithm to deal with more complex flows relevant of turbomachineries, the turbulent flow inside a simplified stage of High-Pressure compressor is considered.
Romain Oguic, Stéphane Viazzo, Sébastien Poncet. A parallelized multidomain compact solver for incompressible turbulent flows in cylindrical geometries. Journal of Computational Physics, 2015, 300, pp.710-731. ⟨10.1016/j.jcp.2015.08.003⟩. ⟨hal-01299082⟩
Adrien Aubert, Sébastien Poncet, Patrice Le Gal, Stephane Viazzo, Michael Le Bars. Velocity and temperature measurements in a turbulent water-filled Taylor–Couette–Poiseuille system. International Journal of Thermal Sciences, 2015, 90, pp. 238-247. ⟨hal-01308638⟩ Plus de détails...
Adrien Aubert, Sébastien Poncet, Patrice Le Gal, Stephane Viazzo, Michael Le Bars. Velocity and temperature measurements in a turbulent water-filled Taylor–Couette–Poiseuille system. International Journal of Thermal Sciences, 2015, 90, pp. 238-247. ⟨hal-01308638⟩
Journal: International Journal of Thermal Sciences
Adrien Aubert, Sébastien Poncet, Patrice Le Gal, Stéphane Viazzo, Michael Le Bars. Velocity and temperature measurements in a turbulent water-filled Taylor–Couette–Poiseuille system. International Journal of Thermal Sciences, 2015, 90, pp.238-247. ⟨10.1016/j.ijthermalsci.2014.12.018⟩. ⟨hal-01308638⟩ Plus de détails...
Motivated by the difficulties encountered by engineers to cool down the rotating shafts of industrial machines, the present work investigates the heat and mass transfers in the rotor-stator gap of a Taylor–Couette system with an axial water flow characterized by an aspect ratio Γ = 50 and a radius ratio η = 8/9. Extensive velocity and temperature measurements have been performed on an experimental set-up for a wide range of the flow parameters: the axial Reynolds number Re and the Taylor number Ta reach the values 1.12 × 104 and 7.9 × 107 respectively. In particular, coherent structures close to the rotating wall were measured by Stereo Particle Image Velocimetry. A correlation for the Nusselt number Nu on the rotating wall is finally provided against the axial Reynolds, Taylor and Prandtl numbers. Nu is proportional to the Taylor number to the power ∼0.13 close to the exponent 1/7 highlighted by an analytical model. This small exponent traduces the control of heat transfers by the rotating viscous layer and thus may explain the difficulty met by engineers to develop strategies for the effective cooling of such rotating apparatus.
Adrien Aubert, Sébastien Poncet, Patrice Le Gal, Stéphane Viazzo, Michael Le Bars. Velocity and temperature measurements in a turbulent water-filled Taylor–Couette–Poiseuille system. International Journal of Thermal Sciences, 2015, 90, pp.238-247. ⟨10.1016/j.ijthermalsci.2014.12.018⟩. ⟨hal-01308638⟩
Journal: International Journal of Thermal Sciences
Bikash Sahoo, Sébastien Poncet, Fotini Labropulu. Suction/Injection Effects on the Swirling Flow of a Reiner-Rivlin Fluid near a Rough Surface. Hindawi Publishing Corporation, 2015, 2015, Article ID 253504, 5 p. ⟨10.1155/2015/253504⟩. ⟨hal-01100098⟩ Plus de détails...
The similarity equations for the Bödewadt flow of a non-Newtonian Reiner-Rivlin fluid, subject to uniform suction/injection, are solved numerically. The conventional no-slip boundary conditions are replaced by corresponding partial slip boundary conditions, owing to the roughness of the infinite stationary disk. The combined effects of surface slip, suction/injection velocity, and cross-viscous parameter on the momentum boundary layer are studied in detail. It is interesting to find that suction dominates the oscillations in the velocity profiles and decreases the boundary layer thickness significantly. On the other hand, injection has opposite effects on the velocity profiles and the boundary layer thickness.
Bikash Sahoo, Sébastien Poncet, Fotini Labropulu. Suction/Injection Effects on the Swirling Flow of a Reiner-Rivlin Fluid near a Rough Surface. Hindawi Publishing Corporation, 2015, 2015, Article ID 253504, 5 p. ⟨10.1155/2015/253504⟩. ⟨hal-01100098⟩
Bikash Sahoo, Sébastien Poncet, Fotini Labropulu. Effects of slip on the Von Kármán swirling flow and heat transfer in a porous medium. Transactions of the Canadian Society for Mechanical Engineering, 2015, 39 (2), pp.357-366. ⟨10.1139/tcsme-2015-0025⟩. ⟨hal-01300117⟩ Plus de détails...
Numerical solutions are obtained for the fully coupled and highly nonlinear system of differential equations, arising due to the steady Kármán flow and heat transfer of a viscous fluid in a porous medium. The conventional no-slip boundary conditions are replaced by partial slip boundary conditions owing to the roughness of the disk surface. Combined effects of the slip λ and porosity γ parameters on the momentum and thermal boundary layers are studied in detail. Both parameters produce the same effects on the mean velocity profiles, such that all velocity components are reduced by increasing either λ or γ. The temperature slip factor β has a dominating influence on the temperature profiles by decreasing the fluid temperature in the whole domain. The porosity parameter strongly decreases the heat transfer coefficient at the wall for low values of β and tends to an asymptotical limit around 0.1 for β 10. The porosity parameter γ increases the moment coefficient at the disk surface, which is found to monotonically decrease with λ .
Bikash Sahoo, Sébastien Poncet, Fotini Labropulu. Effects of slip on the Von Kármán swirling flow and heat transfer in a porous medium. Transactions of the Canadian Society for Mechanical Engineering, 2015, 39 (2), pp.357-366. ⟨10.1139/tcsme-2015-0025⟩. ⟨hal-01300117⟩
Journal: Transactions of the Canadian Society for Mechanical Engineering
Nabila Ait-Moussa, Sébastien Poncet, Abdelrahmane Ghezal. Numerical Simulations of Co- and Counter-Taylor-Couette Flows: Influence of the Cavity Radius Ratio on the Appearance of Taylor Vortices. American Journal of Fluid Dynamics, 2015, 5 (1), pp.17-22. ⟨10.5923/j.ajfd.20150501.02⟩. ⟨hal-01300130⟩ Plus de détails...
Taylor-Couette flows in the annular region between rotating concentric cylinders are studied numerically to determine the combined effects of the co- and counter-rotation of the outer cylinder and the radius ratio on the system response. The computational procedure is based on a finite volume method using staggered grids. The axisymmetric conservative governing equations are solved using the SIMPLER algorithm. One considers the flow confined in a finite cavity with radius ratios η = 0.25, 0.5, 0.8 and 0.97. One has determined the critical points and properties for the bifurcation from the basic circular Couette flow (CCF) to the Taylor Vortex Flow (TVF) state. Indeed, the results are presented in terms of the critical Reynolds number Rei of the inner cylinder that depends on the rotational Reynolds number of the outer cylinder Reo and η. To show the capability of the present code, excellent quantitative agreement has been obtained between the calculations and previous experimental measurements for a wide range of radius ratios and rotation rates.
Nabila Ait-Moussa, Sébastien Poncet, Abdelrahmane Ghezal. Numerical Simulations of Co- and Counter-Taylor-Couette Flows: Influence of the Cavity Radius Ratio on the Appearance of Taylor Vortices. American Journal of Fluid Dynamics, 2015, 5 (1), pp.17-22. ⟨10.5923/j.ajfd.20150501.02⟩. ⟨hal-01300130⟩
Adrien Aubert, Sébastien Poncet, Patrice Le Gal, Stéphane Viazzo, Michel Lebars. Velocity and temperature measurements in a turbulent water-filled Taylor-Couette-Poiseuille system. International Journal of Thermal Sciences, 2015. ⟨hal-01467719⟩ Plus de détails...
Motivated by the difficulties encountered by engineers to cool down the rotating shafts of industrial machines, the present work investigates the heat and mass transfers in the rotor-stator gap of a Taylor–Couette system with an axial water flow characterized by an aspect ratio Γ = 50 and a radius ratio η = 8/9. Extensive velocity and temperature measurements have been performed on an experimental set-up for a wide range of the flow parameters: the axial Reynolds number Re and the Taylor number Ta reach the values 1.12 × 104 and 7.9 × 107 respectively. In particular, coherent structures close to the rotating wall were measured by Stereo Particle Image Velocimetry. A correlation for the Nusselt number Nu on the rotating wall is finally provided against the axial Reynolds, Taylor and Prandtl numbers. Nu is proportional to the Taylor number to the power ∼0.13 close to the exponent 1/7 highlighted by an analytical model. This small exponent traduces the control of heat transfers by the rotating viscous layer and thus may explain the difficulty met by engineers to develop strategies for the effective cooling of such rotating apparatus.
Adrien Aubert, Sébastien Poncet, Patrice Le Gal, Stéphane Viazzo, Michel Lebars. Velocity and temperature measurements in a turbulent water-filled Taylor-Couette-Poiseuille system. International Journal of Thermal Sciences, 2015. ⟨hal-01467719⟩
Journal: International Journal of Thermal Sciences
Sébastien Poncet, Stéphane Viazzo, Oguic Romain. Large eddy simulations of Taylor-Couette-Poiseuille flows in a narrow-gap system. Physics of Fluids, 2014, 26 (10), pp.105108. ⟨10.1063/1.4899196⟩. ⟨hal-01083052⟩ Plus de détails...
The present paper concerns Large-Eddy Simulations (LES) of turbulent Taylor-Couette-Poiseuille flows in a narrow-gap cavity for six different combinations of rotational and axial Reynolds numbers. The in-house numerical code has been first validated in a middle-gap cavity. Two sets of refined LES results, using the Wall-Adapting Local EddyViscosity(WALE) and theDynamic Smagorinsky subgrid-scale models availablewithin an in-house code based on high-order compact schemes, have been then compared with no noticeable difference on the mean flow field and theturbulent statistics. The WALE model enabling a saving of about 12% of computational effort has been finally used to investigate the influence on the hydrodynamics of the swirl parameter N within the range [1.49 − 6.71]. The swirl parameter N, which compares the effects of rotation of the inner cylinder and the axial flowrate, does not influence significantly the mean velocity profiles. Turbulence intensities are enhanced with increasing values of N with remarkably high peak values within the boundary layers. The inner rotating cylinder has a destabilizing effect inducing asymmetric profiles of the Reynolds stress tensor components. The rotor and stator boundary layers exhibit the main characteristics of two-dimensional boundary layers.Turbulence is also mainly at two-component there. Thin coherent structures appearing as negative (resp. positive) spiral rolls are observed along the rotor (resp. stator) side. Their inclination angle depends strongly on the value of the swirl parameter, which fixes the intensity of the crossflow. On the other hand, the intensity and the size of the coherent structures observed within the boundary layers are governed by the effective Reynolds number. For its highest value, they penetrate the whole gap. Finally, the results have been extended to the non-isothermal case in the forced convection regime. A correlation for the Nusselt number along the rotor has been provided showing a much larger dependence on the axial Reynolds number thanexpected from previous published works, while it depends classically on the Taylor number to the power 0.145 and on the Prandtl number to the power 0.3.
Sébastien Poncet, Stéphane Viazzo, Oguic Romain. Large eddy simulations of Taylor-Couette-Poiseuille flows in a narrow-gap system. Physics of Fluids, 2014, 26 (10), pp.105108. ⟨10.1063/1.4899196⟩. ⟨hal-01083052⟩
Stéphane Viazzo, Sébastien Poncet. Numerical simulation of the flow stability in a high aspect ratio Taylor–Couette system submitted to a radial temperature gradient. Computers and Fluids, 2014, 101, pp.15-26. ⟨10.1016/j.compfluid.2014.05.025⟩. ⟨hal-01083054⟩ Plus de détails...
From 28 high-order DNS computations, one investigates the formation of instabilities due to the strong competition between an azimuthal flow induced by rotation and an axial flow due to convection in a tall Taylor–Couette apparatus (gamma=80; eta=0.8) submitted to a radial temperature gradient. One explores the richness of the transition diagram that reports seven different flow patterns appearing either as spiral rolls, wavy vortices or a combination of both depending on the Taylor and Rayleigh numbers. The partial spiral regime observed experimentally by Guillerm (2010) is not recovered at very low Rayleigh numbers. The spatio-temporal properties of the different spirals close to the threshold of the primary instability are fairly predicted and a new insight on the flow and thermal structures of the instabilities is gained from this study. Finally, the distributions of the Nusselt number against the Taylor number are established for various Rayleigh numbers.
Stéphane Viazzo, Sébastien Poncet. Numerical simulation of the flow stability in a high aspect ratio Taylor–Couette system submitted to a radial temperature gradient. Computers and Fluids, 2014, 101, pp.15-26. ⟨10.1016/j.compfluid.2014.05.025⟩. ⟨hal-01083054⟩
Sébastien Poncet. The stability of a thin water layer over a rotating disk revisited. The European Physical Journal Plus, 2014, 129, pp.167. ⟨10.1140/epjp/i2014-14167-2⟩. ⟨hal-01083053⟩ Plus de détails...
The flow driven by a rotating disk of a thin fluid layer in a fixed cylindrical casing is studied by direct numerical simulation and experimental flow visualizations. The characteristics of the flow are first briefly discussed but the focus of this work is to understand the transition to the primary instability. The primary bifurcation is 3D and appears as spectacular sharp-cornered polygonal patterns located along the shroud. The stability diagram is established experimentally in a (Re, G) plane, where G is the aspect ratio of the cavity and Re the rotational Reynolds number and confirmed numerically. The number of vortices scales well with the Ekman number based on the water depth, which confirms the existence of a Stewartsonlayer along the external cylinder. The critical mixed Reynolds number is found to be constant as in other rotating flows involving a shear-layer instability. Hysteresis cycles are observed highlighting the importance of the spin-up and spin-down processes. In some particular cases, a crossflow instability appears under the form of high azimuthal wave number spiral patterns, similar to those observed in a rotor-stator cavity with throughflow and coexists with the polygons. The DNS calculations confirm the experimental results under the flat free surface hypothesis.
Sébastien Poncet. The stability of a thin water layer over a rotating disk revisited. The European Physical Journal Plus, 2014, 129, pp.167. ⟨10.1140/epjp/i2014-14167-2⟩. ⟨hal-01083053⟩
Bikash Sahoo, Saied Abbasbandy, Sébastien Poncet. A brief note on the computation of the Bödewadt flow with Navier slip boundary conditions. Computers and Fluids, 2014, 90, pp.133-137. ⟨10.1016/j.compfluid.2013.11.020⟩. ⟨hal-00976676⟩ Plus de détails...
In this short communication, numerical solutions are obtained for the steady Bödewadt flow of a viscous fluid subject to partial slip boundary conditions. The resulting system of nonlinear and fully coupled similarity equations are integrated accurately by a finite difference scheme and by the Keller-box method. It is observed that slip has a prominent effect on the velocity field, reducing drastically the axial velocity and the pressure. Moreover, the torque required to maintain the disk at rest decreases for increasing values of slip.
Bikash Sahoo, Saied Abbasbandy, Sébastien Poncet. A brief note on the computation of the Bödewadt flow with Navier slip boundary conditions. Computers and Fluids, 2014, 90, pp.133-137. ⟨10.1016/j.compfluid.2013.11.020⟩. ⟨hal-00976676⟩
Guillaume Fontaine, Sébastien Poncet, Eric Serre. Multidomain Extension of a Pseudospectral Algorithm for the Direct Simulation of Wall-Confined Rotating Flows. M. Azaiez, H. El Fekih, J.S. Hesthaven. Lecture Notes in Computational Science and Engineering, 95, Springer, pp.261 - 271, 2014, ⟨10.1007/978-3-319-01601-6_21⟩. ⟨hal-01098589⟩ Plus de détails...
In this work, we improve an existing pseudospectral algorithm, in order to extend its properties to a multidomain patching of a rotating cavity. Viscous rotating flows have been widely studied over the last decades, either on industrial or aca-demic approaches. Nevertheless, the range of Reynolds numbers reached in indus-trial devices implies very high resolutions of the spatial problem, which are clearly unreachable using a monodomain approach. Hence, we worked on the multido-main extension of the existing divergence-free Navier-Stokes solver with a Schur approach. The particularity of such an approach is that it does not require any sub-domain superposition: the value of a variable on the boundary between two adjacent subdomains is treated as a boundary condition of a local Helmholtz solver. This value is computed on a direct way via a so-called continuity influence matrix and the derivative jump of an homogeneous solution computed independently on each subdomain. Such a method is known to have both good scalability and accuracy. It has been validated on two well documented three-dimensional rotating flows.
Guillaume Fontaine, Sébastien Poncet, Eric Serre. Multidomain Extension of a Pseudospectral Algorithm for the Direct Simulation of Wall-Confined Rotating Flows. M. Azaiez, H. El Fekih, J.S. Hesthaven. Lecture Notes in Computational Science and Engineering, 95, Springer, pp.261 - 271, 2014, ⟨10.1007/978-3-319-01601-6_21⟩. ⟨hal-01098589⟩
Sébastien Poncet, Thien Duy Nguyen, Souad Harmand, Julien Pellé, Riccardo da Soghe, et al.. Turbulent impinging jet flow into an unshrouded rotor-stator system: Hydrodynamics and heat transfer. International Journal of Heat and Fluid Flow, 2013, 44, pp.719-734. ⟨10.1016/j.ijheatfluidflow.2013.10.001⟩. ⟨hal-00976669⟩ Plus de détails...
New calculations using an innovative Reynolds Stress Model are compared to velocity measurements performed by Particle Image Velocimetry technique and the predictions of a k-w SST model in the case of an impinging jet flow onto a rotating disk in a discoidal and unshrouded rotor-stator system. The cavity is characterized by a dimensionless spacing interval G=0.02 and a low aspect ratio for the jet e/D=0.25. Jet Reynolds numbers ranging from 17200 to 43000 and rotational Reynolds numbers between 33000 and 532000 are considered. Three flow regions have been identified: a jet-dominated flow area at low radii characterized by a zero tangential velocity, a mixed region at intermediate radii and rotation-dominated flow region outwards. For all parameters, turbulence, which tends to the isotropic limit in the core, is much intense in a region located after the impingement zone. A relative good agreement between the PIV measurements and the predictions of the RSM has been obtained in terms of the radial distributions of the core-swirl ratio and of the turbulence intensities. The k-wSST model overestimates these flow characteristics in the jet dominated area. For the thermal field, the heat transfers are enhanced in the jet dominated region and decreases towards the periphery of the cavity. The jet Reynolds number appears to have a preponderant effect compared to the rotational one on the heat transfer distribution. The two RANS modelings compare quite well with the heat transfer measurements for these ranges of parameters.
Sébastien Poncet, Thien Duy Nguyen, Souad Harmand, Julien Pellé, Riccardo da Soghe, et al.. Turbulent impinging jet flow into an unshrouded rotor-stator system: Hydrodynamics and heat transfer. International Journal of Heat and Fluid Flow, 2013, 44, pp.719-734. ⟨10.1016/j.ijheatfluidflow.2013.10.001⟩. ⟨hal-00976669⟩
Journal: International Journal of Heat and Fluid Flow
Bikash Sahoo, Sébastien Poncet. Blasius flow and heat transfer of fourth-grade fluid with slip. Applied Mathematics and Mechanics, 2013, 34 (12), pp.1465-1480. ⟨10.1007/s10483-013-1760-6⟩. ⟨hal-00975631⟩ Plus de détails...
This investigation deals with the effects of slip, magnetic field, and non-Newtonian flow parameters on the flow and heat transfer of an incompressible, electrically conducting fourth-grade fluid past an infinite porous plate. The heat transfer analysis is carried out for two heating processes. The system of highly non-linear differential equations is solved by the shooting method with the fourth-order Runge-Kutta method for moderate values of the parameters. The effective Broyden technique is adopted in order to improve the initial guesses and to satisfy the boundary conditions at infinity. An exceptional cross-over is obtained in the velocity profile in the presence of slip. The fourth-grade fluid parameter is found to increase the momentum boundary layer thickness, whereas the slip parameter substantially decreases it. Similarly, the non-Newtonian fluid parameters and the slip have opposite effects on the thermal boundary layer thickness.
Bikash Sahoo, Sébastien Poncet. Blasius flow and heat transfer of fourth-grade fluid with slip. Applied Mathematics and Mechanics, 2013, 34 (12), pp.1465-1480. ⟨10.1007/s10483-013-1760-6⟩. ⟨hal-00975631⟩
Sébastien Poncet, Stéphane Viazzo, Adrien Aubert, Riccardo da Soghe, Cosimo Bianchini. Turbulent Couette-Taylor flows with endwall effects: a numerical benchmark. International Journal of Heat and Fluid Flow, 2013, 44, pp.229-238. ⟨10.1016/j.ijheatfluidflow.2013.05.018⟩. ⟨hal-00975636⟩ Plus de détails...
The accurate prediction of fluid flow within rotating systems has a primary role for the reliability and performance of rotating machineries. The selection of a suitable model to account for the effects of turbulence on such complex flows remains an open issue in the literature. This paper reports a numerical benchmark of different approaches available within commercial CFD solvers together with results obtained by means of in-house developed or open-source available research codes exploiting a suitable Reynolds Stress Model (RSM) closure, Large Eddy Simulation (LES) and a direct numerical simulation (DNS). The predictions are compared to the experimental data of Burin et al. (2010) in an original enclosed Couette-Taylor apparatus with endcap rings. The results are discussed in details for both the mean and turbulent fields. A particular attention has been turned to the scaling of the turbulent angular momentum G with the Reynolds number Re. By DNS, G is found to be proportional to Rea, the exponent a = 1.9 being constant in our case for the whole range of Reynolds numbers. Most of the approaches predict quite well the good trends apart from the k-w SST model, which provides relatively poor agreement with the experiments even for the mean tangential velocity profile. Among the RANS models, even though no approach appears to be fully satisfactory, the RSM closure offers the best overall agreement.
Sébastien Poncet, Stéphane Viazzo, Adrien Aubert, Riccardo da Soghe, Cosimo Bianchini. Turbulent Couette-Taylor flows with endwall effects: a numerical benchmark. International Journal of Heat and Fluid Flow, 2013, 44, pp.229-238. ⟨10.1016/j.ijheatfluidflow.2013.05.018⟩. ⟨hal-00975636⟩
Journal: International Journal of Heat and Fluid Flow
Souad Harmand, Julien Pellé, Sébastien Poncet, Igor Shevchuk. Review of fluid flow and convective heat transfer within rotating disk cavities with impinging jet. International Journal of Thermal Sciences, 2013, 67, pp.1-30. ⟨10.1016/j.ijthermalsci.2012.11.009⟩. ⟨hal-00975626⟩ Plus de détails...
Fluid flow and convective heat transfer in rotor-stator configurations, which are of great importance in different engineering applications, are treated in details in this review. The review focuses on convective heat transfer in predominantly outward air flow in the rotor-stator geometries with and without impinging jets and incorporates two main parts, namely, experimental / theoretical methodologies and geometries/results. Experimental methodologies include naphthalene sublimation techniques, steadystate (thin layer) and transient (thermochromic liquid crystals) thermal measurements, thermocouples and infra-red cameras, hot-wire anemometry, laser Doppler and particle image velocimetry, laser plane and smoke generator. Theoretical approaches incorporate modern CFD computational tools (DNS, LES, RANS etc). Geometries and results part being mentioned starting from simple to complex elucidates cases of a free rotating disk, a single disk in the crossflow, single jets impinging onto stationary and rotating disk, rotor-stator systems without and with impinging single jets, as well as multiple jets. Conclusions to the review outline perspectives of the further extension of the investigations of different kinds of the rotor-stator systems and their applications in engineering practice.
Souad Harmand, Julien Pellé, Sébastien Poncet, Igor Shevchuk. Review of fluid flow and convective heat transfer within rotating disk cavities with impinging jet. International Journal of Thermal Sciences, 2013, 67, pp.1-30. ⟨10.1016/j.ijthermalsci.2012.11.009⟩. ⟨hal-00975626⟩
Journal: International Journal of Thermal Sciences
Noele Peres, Sébastien Poncet, Eric Serre. A 3D pseudospectral method for cylindrical coordinates. Application to the simulations of rotating cavity flows. Journal of Computational Physics, 2012, 231, pp.6290-6305. ⟨10.1016/j.jcp.2012.04.033⟩. ⟨hal-00822026⟩ Plus de détails...
The present work proposes a collocation spectral method for solving the three-dimensional Navier-Stokes equations using cylindrical coordinates. The whole diameter -R < r < R is discretized with an even number of radial Gauss-Lobatto collocation points and an angular shift is introduced in the Fourier transform that avoid pole and parity conditions usually required. The method keeps the spectral convergence that reduces the number of grid points with respect to lower-order numerical methods. The grid-points distribution densifies the mesh only near the boundaries that makes the algorithm well-suited to simulate rotating cavity flows where thin layers develop along the walls. Comparisons with reliable experimental and numerical results of the literature show good quantitative agreements for flows driven by rotating discs in tall cylinders and thin inter-disc cavities. Associated to a spectral vanishing viscosity [E. Séverac, E. Serre, A spectral vanishing viscosity for the LES of turbulent flows within rotating cavities, J. Comp. Phys. 226 (2007) 1234-1255], the method provides very promising LES results of turbulent cavity flows.
Noele Peres, Sébastien Poncet, Eric Serre. A 3D pseudospectral method for cylindrical coordinates. Application to the simulations of rotating cavity flows. Journal of Computational Physics, 2012, 231, pp.6290-6305. ⟨10.1016/j.jcp.2012.04.033⟩. ⟨hal-00822026⟩
Thien Nguyen, Julien Pellé, Souad Harmand, Sébastien Poncet. PIV measurements of an air jet impinging on an open rotor-stator system. Experiments in Fluids, 2012, 53, pp.401-412. ⟨10.1007/s00348-012-1298-0⟩. ⟨hal-00822034⟩ Plus de détails...
The current work experimentally investigates the flow characteristics of an air jet impinging on an open rotor-stator system with a low non-dimensional spacing, G = 0.02, and with a very low aspect ratio, e/D = 0.25. The rotational Reynolds numbers varied from 33000 to 532000, while the jet Reynolds numbers ranged from 17200 to 43000. Particle image velocimetry (PIV) measurements were taken along the entire disk diameter in three axial planes. From the obtained PIV velocity fields, the flow statistics were computed. A recirculation flow region, which was centered at the impingement point and possessed high turbulence intensities, was observed. Local peaks in root-mean-square fluctuating velocity distributions appeared in the recirculation region and near the periphery, respectively. Proper orthogonal decomposition analysis was applied to the cases of the jet impinging on the rotor with and without rotation to reveal the coherent structures in the jet region.
Thien Nguyen, Julien Pellé, Souad Harmand, Sébastien Poncet. PIV measurements of an air jet impinging on an open rotor-stator system. Experiments in Fluids, 2012, 53, pp.401-412. ⟨10.1007/s00348-012-1298-0⟩. ⟨hal-00822034⟩
Bikash Sahoo, Sébastien Poncet. Effects of slip on steady Bödewadt flow of a non-Newtonian fluid. Communication Nonlinear Science Numerical Simulation, 2012, 17, pp.4181-4191. ⟨10.1016/j.cnsns.2012.02.031⟩. ⟨hal-00822028⟩ Plus de détails...
The steady flow arising due to the rotation of a non-Newtonian fluid at a larger distance from a stationary disk is extended to the case where the disk surface admits partial slip. The constitutive equation of the non-Newtonian fluid is modeled by that for a Reiner- Rivlin fluid. The momentum equation gives rise to a highly nonlinear boundary value problem. Numerical solution of the governing nonlinear equations are obtained over the entire range of the physical parameters. The effects of slip and non-Newtonian fluid characteristics on the momentum boundary layer are discussed in details. It is observed that slip has prominent effect on the velocity field, whereas a predominant influence of the non-Newtonian parameter is observed on the moment coefficient.
Bikash Sahoo, Sébastien Poncet. Effects of slip on steady Bödewadt flow of a non-Newtonian fluid. Communication Nonlinear Science Numerical Simulation, 2012, 17, pp.4181-4191. ⟨10.1016/j.cnsns.2012.02.031⟩. ⟨hal-00822028⟩
Journal: Communication Nonlinear Science Numerical Simulation
Fontaine G., Poncet S., Serre E.. Multidomain extension of a divergence free pseudo-spectral algorithm for the DNS of wall-confined rotating flows. Lectures notes in comp. Sc. and Eng., 95, Springer, pp.261--271, 2012, 978-3-319-01601-6. ⟨hal-01313536⟩ Plus de détails...
Fontaine G., Poncet S., Serre E.. Multidomain extension of a divergence free pseudo-spectral algorithm for the DNS of wall-confined rotating flows. Lectures notes in comp. Sc. and Eng., 95, Springer, pp.261--271, 2012, 978-3-319-01601-6. ⟨hal-01313536⟩
Date de publication: 01-01-2012
2011
Sébastien Poncet, Laurie Dahlberg. The legacy of Henri Victor Regnault in the arts and sciences. International Journal of Arts and Sciences, 2011, 4 (13), pp.377-400. ⟨hal-00678894⟩ Plus de détails...
The 21st of July 2010 marked the bicentennial of the birth of Henri Victor Regnault, a famous French chemist and physicist and a pioneer of paper photography. During his lifetime, he received many honours and distinctions for his invaluable scientific contributions, especially to experimental thermodynamics. Colleague of the celebrated chemist Louis-Joseph Gay-Lussac (1778-1850) at the École des Mines and mentor of William Thomson (1824-1907) at the École Polytechnique, he is nowadays conspicuously absent from all the textbooks and reviews (Hertz, 2004) dealing with thermodynamics. This paper is thus the opportunity to recall his major contributions to the field of experimental thermodynamics but also to the nascent field, in those days, of organic chemistry. Avid amateur of photography, he devoted more than twenty years of his life to his second passion. Having initially taken up photography in the 1840s as a potential tool for scientific research, he ultimately made many more photographs for artistic and self-expressive purposes than scientific ones. He was a founding member of the Société Héliographique in 1851 and of the Société Française de Photographie in 1854. Like his scientific work, his photography was quickly forgotten upon his death, but has begun to attract new respect and recognition.
Sébastien Poncet, Laurie Dahlberg. The legacy of Henri Victor Regnault in the arts and sciences. International Journal of Arts and Sciences, 2011, 4 (13), pp.377-400. ⟨hal-00678894⟩
Journal: International Journal of Arts and Sciences
Bikash Sahoo, Sébastien Poncet. Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial slip boundary condition. International Journal of Heat and Mass Transfer, 2011, 54, pp.5010-5019. ⟨10.1016/j.ijheatmasstransfer.2011.07.015⟩. ⟨hal-00678884⟩ Plus de détails...
Non-Newtonian boundary layer flow and heat transfer over an exponentially stretching sheet with partial slip boundary condition has been studied in this paper. The flow is subject to a uniform transverse magnetic field. The heat transfer analysis has been carried out for two heating processes, namely (i) with prescribed surface temperature (PST), and (ii) prescribed heat flux (PHF). Suitable similarity transformations are used to reduce the resulting highly nonlinear partial differential equations into ordinary differential equations. An effective second order numerical scheme has been adopted to solve the obtained differen- tial equations. The important finding in this communication is the combined effects of the partial slip and the third grade fluid parameters on the velocity, skin-friction coefficient and the temperature boundary layer. It is found that the third grade fluid parameter increases the momentum boundary layer thickness and decreases the thermal boundary layer thickness.
Bikash Sahoo, Sébastien Poncet. Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial slip boundary condition. International Journal of Heat and Mass Transfer, 2011, 54, pp.5010-5019. ⟨10.1016/j.ijheatmasstransfer.2011.07.015⟩. ⟨hal-00678884⟩
Journal: International Journal of Heat and Mass Transfer
Stéphane Viazzo, Sébastien Poncet, Eric Serre, Anthony Randriamampianina, Patrick Bontoux. High-order Large Eddy Simulations of Confined Rotor-Stator Flows. Flow, Turbulence and Combustion, 2011, 88, pp.63-75. ⟨10.1007/s10494-011-9345-0⟩. ⟨hal-00678841⟩ Plus de détails...
In many engineering and industrial applications, the investigation of rotating turbulent flow is of great interest. In rotor-stator cavities, the centrifugal and Coriolis forces have a strong influence on the turbulence by producing a secondary flow in the meridian plane composed of two thin boundary layers along the disks separated by a non-viscous geostrophic core. Most numerical simulations have been performed using RANS and URANS modelling, and very few investigations have been performed using LES. This paper reports on quantitative comparisons of two high-order LES methods to predict a turbulent rotor-stator flow at the rotational Reynolds number Re=400000. The classical dynamic Smagorinsky model for the subgrid-scale stress (Germano et al., Phys Fluids A 3(7):1760-1765, 1991) is compared to a spectral vanishing viscosity technique (Séverac & Serre, J Comp Phys 226(2):1234-1255, 2007). Numerical results include both instantaneous data and postprocessed statistics. The results show that both LES methods are able to accurately describe the unsteady flow structures and to satisfactorily predict mean velocities as well as Reynolds stress tensor components. A slight advantage is given to the spectral SVV approach in terms of accuracy and CPU cost. The strong improvements obtained in the present results with respect to RANS results confirm that LES is the appropriate level of modelling for flows in which fully turbulent and transition regimes are involved.
Stéphane Viazzo, Sébastien Poncet, Eric Serre, Anthony Randriamampianina, Patrick Bontoux. High-order Large Eddy Simulations of Confined Rotor-Stator Flows. Flow, Turbulence and Combustion, 2011, 88, pp.63-75. ⟨10.1007/s10494-011-9345-0⟩. ⟨hal-00678841⟩
Stéphane Viazzo, Sébastien Poncet, Eric Serre, Anthony Randriamampianina, Patrick Bontoux. High-order Large Eddy Simulations of Confined Rotor-Stator Flows. Flow, Turbulence and Combustion, 2011, 88, pp.63-75. ⟨10.1007/s10494-011-9345-0⟩. ⟨hal-00822030⟩ Plus de détails...
In many engineering and industrial applications, the investigation of rotating turbulent flow is of great interest. In rotor-stator cavities, the centrifugal and Coriolis forces have a strong influence on the turbulence by producing a secondary flow in the meridian plane composed of two thin boundary layers along the disks separated by a non-viscous geostrophic core. Most numerical simulations have been performed using RANS and URANS modelling, and very few investigations have been performed using LES. This paper reports on quantitative comparisons of two high-order LES methods to predict a turbulent rotor-stator flow at the rotational Reynolds number Re=400000. The classical dynamic Smagorinsky model for the subgrid-scale stress (Germano et al., Phys Fluids A 3(7):1760-1765, 1991) is compared to a spectral vanishing viscosity technique (Séverac & Serre, J Comp Phys 226(2):1234-1255, 2007). Numerical results include both instantaneous data and postprocessed statistics. The results show that both LES methods are able to accurately describe the unsteady flow structures and to satisfactorily predict mean velocities as well as Reynolds stress tensor components. A slight advantage is given to the spectral SVV approach in terms of accuracy and CPU cost. The strong improvements obtained in the present results with respect to RANS results confirm that LES is the appropriate level of modelling for flows in which fully turbulent and transition regimes are involved.
Stéphane Viazzo, Sébastien Poncet, Eric Serre, Anthony Randriamampianina, Patrick Bontoux. High-order Large Eddy Simulations of Confined Rotor-Stator Flows. Flow, Turbulence and Combustion, 2011, 88, pp.63-75. ⟨10.1007/s10494-011-9345-0⟩. ⟨hal-00822030⟩
Sébastien Poncet, Sofia Haddadi, Stéphane Viazzo. Numerical modeling of fluid flow and heat transfer in a narrow Taylor-Couette-Poiseuille system. International Journal of Heat and Fluid Flow, 2010, 32, pp.128-144. ⟨10.1016/j.ijheatfluidflow.2010.08.003⟩. ⟨hal-00678877⟩ Plus de détails...
We consider turbulent flows in a differentially heated Taylor-Couette system with an axial Poiseuille flow. The numerical approach is based on the Reynolds Stress Modeling (RSM) of Elena and Schiestel widely validated in various rotor-stator cavities with throughflow. To show the capability of the present code, our numerical predictions are compared very favorably to the velocity measurements of Escudier and Gouldson in the isothermal case, for both the mean and turbulent fields. The RSM model improves, in particular, the predictions of the k-eps model of Naser. Then, the second order model is applied for a large range of rotational Reynolds and Prandtl numbers, flow rate coefficient in a very narrow cavity of radius ratio s=0.961 and aspect ratio L=0.013. Temperature gradients are imposed between the incoming fluid and the inner and outer cylinders. The mean hydrodynamic and thermal fields reveal three distinct regions across the radial gap with a central region of almost constant axial and tangential mean velocities and constant mean temperature. Turbulence, which is weakly anisotropic, is mainly concentrated in that region and vanishes towards the cylinders. The mean velocity distributions are not clearly affected by the rotational Reynolds number and the flow rate coefficient. The effects of the flow parameters on the thermal field are more noticeable and considered in details. Correlations for the averaged Nusselt numbers along both cylinders are finally provided according to the flow control parameters.
Sébastien Poncet, Sofia Haddadi, Stéphane Viazzo. Numerical modeling of fluid flow and heat transfer in a narrow Taylor-Couette-Poiseuille system. International Journal of Heat and Fluid Flow, 2010, 32, pp.128-144. ⟨10.1016/j.ijheatfluidflow.2010.08.003⟩. ⟨hal-00678877⟩
Journal: International Journal of Heat and Fluid Flow
Sébastien Poncet, Marie-Pierre Chauve. Curvature effects on the instabilities of Batchelor rotating disk flows. International Journal of Fluid Mechanics Research, 2010, 37 (4), pp.343-358. ⟨10.1615/InterJFluidMechRes.v37.i4.40⟩. ⟨hal-00678851⟩ Plus de détails...
The stability of a Batchelor flow enclosed between a stationary and a rotating disk with a central hub is investigated by extensive experimental visualizations and direct numerical simulations. The first instability appears as circular rolls (CR), which propagate along the stator towards the rotation axis. Above a second threshold, spiral rolls (SRI) appear at the periphery of the cavity due to the destabilization of the boundary layer along the external cylinder. These spirals coexist with the circular rolls in the experiment. For the first time, the presence of an inner rotating hub, which is of major industrial importance, measured by the influence of the curvature parameter has been studied experimentally. This parameter strongly modifies the wave number of the instabilities as well as the angle of the spirals. Finally, for a given geometry, a very good agreement on the characteristics of these instabilities is obtained between the experimental and numerical approaches.
Sébastien Poncet, Marie-Pierre Chauve. Curvature effects on the instabilities of Batchelor rotating disk flows. International Journal of Fluid Mechanics Research, 2010, 37 (4), pp.343-358. ⟨10.1615/InterJFluidMechRes.v37.i4.40⟩. ⟨hal-00678851⟩
Journal: International Journal of Fluid Mechanics Research
Brian Launder, Sébastien Poncet, Eric Serre. Laminar, transitional, and turbulent flows in rotor-stator cavities. Annual Review of Fluid Mechanics, 2010, 42 (1), pp.229-248. ⟨10.1146/annurev-fluid-121108-145514⟩. ⟨hal-00678846⟩ Plus de détails...
This article reviews the range of flows that may be created within thin cylindrical or annular cavities due to the rotation of one of the confining disks. At low Reynolds numbers, the rotation gives rise to an axisymmetric, radially outward motion near the rotor with a return flow along the stationary disk. As the Reynolds number is raised, this base flow gives way to a shear flow populated by discrete vortices, whether of cylindrical or spiral form, near both the rotating and stationary disks. At Reynolds numbers high enough for turbulent flow to occur, in the twentieth century both experimental and computational studies treated the flow as axisymmetric and steady. Recent research has shown, however, that complex organized structures also persist in the turbulent regime.
Brian Launder, Sébastien Poncet, Eric Serre. Laminar, transitional, and turbulent flows in rotor-stator cavities. Annual Review of Fluid Mechanics, 2010, 42 (1), pp.229-248. ⟨10.1146/annurev-fluid-121108-145514⟩. ⟨hal-00678846⟩
Sébastien Poncet, Eric Serre. High-order LES of turbulent heat transfer in a rotor–stator cavity. International Journal of Heat and Fluid Flow, 2009, 30, pp.590-601. ⟨10.1016/j.ijheatfluidflow.2009.01.011⟩. ⟨hal-00409169⟩ Plus de détails...
The present work examines the turbulent flow in an enclosed rotor–stator system subjected to heat transfer effects. Besides their fundamental importance as three-dimensional prototype flows, such flows arise in many industrial applications but also in many geophysical and astrophysical settings. Large eddy simulations(LES) are here performed using a spectral vanishing viscosity technique. The LES results have already been favorably compared to velocity measurements in the isothermal case (Séverac et al. 2007) for a large range of Reynolds numbers in an annular cavity of large aspect ratio and weak curvature parameter. The purpose of this paper is to extend these previous results in the non-isothermal case using the Boussinesq approximation to take into account the buoyancy effects. Thus, the effects of thermal convection have been examined for a turbulent flow of air in the same rotor–stator system for Rayleigh numbers up to 100 millions. These LES results provide accurate, instantaneous quantities which are of interest in understanding the physics of turbulent flows and heat transfers in an interdisk cavity. Even at high Rayleigh numbers, the structure of the iso-values of the instantaneous normal temperature gradient at the disk surfaces resembles the one of the iso-values of the tangential velocity with large spiral arms along the rotor and more thin structures along the stator. The averaged results show small effects of density variation on the mean and turbulent fields. The turbulent Prandtl number is a decreasing function of the distance to the wall with 1.4 close to the disks and about 0.3 in the outer layers. The local Nusselt number is found to be proportional to the local Reynolds number to the power 0.7. The evolution of the averaged Bolgiano length scale with the Rayleigh number indicates that temperature fluctuations may have a large influence on the dynamics only at the largest scales of the system for Ra larger than 10 millions, since the averaged Bolgiano length scale remains lower than the thermal boundary layer thicknesses.
Sébastien Poncet, Eric Serre. High-order LES of turbulent heat transfer in a rotor–stator cavity. International Journal of Heat and Fluid Flow, 2009, 30, pp.590-601. ⟨10.1016/j.ijheatfluidflow.2009.01.011⟩. ⟨hal-00409169⟩
Journal: International Journal of Heat and Fluid Flow
Sébastien Poncet, Eric Serre, Patrice Le Gal. Revisiting the two first instabilities of the flow in an annular rotor-stator cavity. Physics of Fluids, 2009, 21, pp.064106. ⟨10.1063/1.3156859⟩. ⟨hal-00418838⟩ Plus de détails...
Sébastien Poncet, Eric Serre, Patrice Le Gal. Revisiting the two first instabilities of the flow in an annular rotor-stator cavity. Physics of Fluids, 2009, 21, pp.064106. ⟨10.1063/1.3156859⟩. ⟨hal-00418838⟩
Fadi Abdel Nour, Sébastien Poncet, Roger Debuchy, Gérard Bois. A Combined analytical, experimental and numerical investigation of turbulent air flow behaviour in a rotor-stator cavity. Mechanics & Industry, 2009, 10 (3-4), pp.195-201. ⟨10.1051/meca/2009065⟩. ⟨hal-00412203⟩ Plus de détails...
The present work considers the turbulent air flow inside an annular high speed rotor-stator cavity opened to the atmosphere at the periphery, where the pre-swirl ratio of the fluid is low. The interdisk spacing is sufficiently large so that the boundary layers developed on each disk are separated and the flow belongs to the regime IV of Daily and Nece (ASME J. Basic Eng. 82 (1960) 217–232). In such a system, the solid body rotation of the core predicted by Batchelor (J. Mech. Appl. Math. 4 (1951) 29–41) in case of infinite disks is not always observed: the flow behaviour in the whole interdisk spacing is governed by the level of the pre-swirl velocity of the fluid which is closely linked to the peripheral geometry (Debuchy et al., Int. J. Rotating Machinery, (2007)). In the first part of the paper, experimental results performed by hot-wire probes introduced through the stator including mean radial and tangential velocity components, as well as three turbulent correlations, are presented for several peripheral boundary conditions leading to the same value of the pre-swirl ratio. In the second part, comparisons between experiments, numerical and analytical results are provided. The numerical approach is based on the Reynolds Stress Modeling (RSM) developed by Elena and Schiestel (Int. J. Heat Fluid Flow 17 (1996) 283–289). A good agreement between the different approaches is obtained for the mean and turbulent fields and especially for the distribution of the core swirl ratio.
Fadi Abdel Nour, Sébastien Poncet, Roger Debuchy, Gérard Bois. A Combined analytical, experimental and numerical investigation of turbulent air flow behaviour in a rotor-stator cavity. Mechanics & Industry, 2009, 10 (3-4), pp.195-201. ⟨10.1051/meca/2009065⟩. ⟨hal-00412203⟩
Sofia Haddadi, Sébastien Poncet. Turbulence Modeling of Torsional Couette Flows. International Journal of Rotating Machinery, 2008, 2008, pp.Article ID 635138. ⟨10.1155/2008/635138⟩. ⟨hal-00356495⟩ Plus de détails...
The present study considers the numerical modeling of the turbulent flow inside a rotor-stator cavity subjected or not to a superimposed throughflow. Extensive numerical predictions based on one-point statistical modeling using a low Reynolds number second-order full stress transport closure (RSM model) are performed mainly in the case of turbulent flows with merged boundary layers known as turbulent torsional Couette flows and belonging to the regime III of Daily and Nece (1960). The RSM model has already shown its capability of predicting accurately the mean and turbulent fields in various rotating disk configurations. For the first time, a detailed mapping of the hydrodynamic flow over a wide range of rotational Reynolds numbers, aspect ratios of the cavity and flow rate coefficients is here provided in the turbulent torsional Couette flow regime.
Sofia Haddadi, Sébastien Poncet. Turbulence Modeling of Torsional Couette Flows. International Journal of Rotating Machinery, 2008, 2008, pp.Article ID 635138. ⟨10.1155/2008/635138⟩. ⟨hal-00356495⟩
Journal: International Journal of Rotating Machinery
Sébastien Poncet, Marie-Pierre Chauve, Patrice Le Gal. Lois analytiques pour les écoulements en cavité rotor-stator. Mechanics & Industry, 2008, 9 (3), pp.227-236. ⟨10.1051/meca:2088029⟩. ⟨hal-00297731⟩ Plus de détails...
Cette étude concerne les écoulements de type rotor-stator à couches limites séparées soumis à un flux axial. Suivant l'analyse faite par Schlichting (1979) dans le cas d'un disque tournant de rayon infini, on détermine des lois analytiques simples permettant de prévoir le coefficient d'entraînement K du fluide à partir des paramètres de contrôle (taux de rotation, flux, espace interdisque, taux de prérotation) pour divers régimes d'écoulement (laminaire ou turbulent) et différentes configurations (géométrie, rotor lisse, rugueux ou aileté). Cette approche analytique est validée par d'extensives mesures de vitesse et de pression.
Sébastien Poncet, Marie-Pierre Chauve, Patrice Le Gal. Lois analytiques pour les écoulements en cavité rotor-stator. Mechanics & Industry, 2008, 9 (3), pp.227-236. ⟨10.1051/meca:2088029⟩. ⟨hal-00297731⟩
Sébastien Poncet, Roland Schiestel, Romain Monchaux. Turbulence modeling of the Von Karman flow: viscous and inertial stirrings. International Journal of Heat and Fluid Flow, 2008, 29 (1), pp.62-74. ⟨10.1016/j.ijheatfluidflow.2007.07.005⟩. ⟨hal-00202922⟩ Plus de détails...
The present work considers the turbulent Von Karman flow generated by two counter-rotating smooth flat (viscous stirring) or bladed (inertial stirring) disks. Numerical predictions based on one-point statistical modeling using a low Reynolds number second-order full stress transport closure (RSM model) are compared to velocity measurements performed at CEA (Commissariat à l'Energie Atomique, France). The main and significant novelty of this paper is the use of a drag force in the momentum equations to reproduce the effects of inertial stirring instead of modelling the blades themselves. The influences of the rotational Reynolds number, the aspect ratio of the cavity, the rotating disk speed ratio and of the presence or not of impellers are investigated to get a precise knowledge of both the dynamics and the turbulence properties in the Von Karman configuration. In particular, we highlighted the transition between the merged and separated boundary layer regimes and the one between the Batchelor (1951) and the Stewartson (1953) flow structures in the smooth disk case. We determined also the transition between the one cell and the two cell regimes for both viscous and inertial stirrings.
Sébastien Poncet, Roland Schiestel, Romain Monchaux. Turbulence modeling of the Von Karman flow: viscous and inertial stirrings. International Journal of Heat and Fluid Flow, 2008, 29 (1), pp.62-74. ⟨10.1016/j.ijheatfluidflow.2007.07.005⟩. ⟨hal-00202922⟩
Journal: International Journal of Heat and Fluid Flow
Sébastien Poncet, Anthony Randriamampianina. Three-dimensional turbulent boundary layer in a shrouded rotating system. Flow, Turbulence and Combustion, 2008, 80 (1), pp.107-117. ⟨10.1007/s10494-007-9083-5⟩. ⟨hal-00192950⟩ Plus de détails...
A three-dimensional direct numerical simulation is combined with a laboratory study to describe the turbulent flow in an enclosed annular rotor-stator cavity characterized by a large aspect ratio G=(b-a)/h=18.32 and a small radius ratio a/b=0.152, where a and b are the inner and outer radii of the rotating disk and h is the interdisk spacing. The rotation rate $\Omega$ considered is equivalent to the rotational Reynolds number $Re=\Omega b^2/\nu=9.5 \times 10^4$ ($\nu$ the kinematic viscosity of water). This corresponds to a value at which experiment has revealed that the stator boundary layer is turbulent, whereas the rotor boundary layer is still laminar. Comparisons of the computed solution with velocity measurements have given good agreement for the mean and turbulent fields. The results enhance evidence of weak turbulence by comparing the turbulence properties with available data in the literature (Lygren & Andersson, J Fluid Mech 426:297-326, 2001). An approximately self-similar boundary layer behavior is observed along the stator. The wall-normal variations of the structural parameter and of characteristic angles confirm that this boundary layer is three-dimensional. A quadrant analysis (Kang et al, Phys Fluids 10:2315-2322, 1998) of conditionally averaged velocities shows that the asymmetries obtained are dominated by Reynolds stress-producing events in the stator boundary layer. Moreover, Case 1 vortices (with a positive wall induced velocity) are found to be the major source of generation of special strong events, in agreement with the conclusions of Lygren and Andersson (J Fluid Mech 426:297-326, 2001).
Sébastien Poncet, Anthony Randriamampianina. Three-dimensional turbulent boundary layer in a shrouded rotating system. Flow, Turbulence and Combustion, 2008, 80 (1), pp.107-117. ⟨10.1007/s10494-007-9083-5⟩. ⟨hal-00192950⟩
Eric Séverac, Sébastien Poncet, Eric Serre, Marie-Pierre Chauve. Large eddy simulation and measurements of turbulent enclosed rotor-stator flows. Physics of Fluids, 2007, 19 (8), pp.085113. ⟨10.1063/1.2759530⟩. ⟨hal-00170072⟩ Plus de détails...
Turbulent flows are studied in an actual enclosed rotor-stator configuration with a rotating hub and a stationary shroud. Besides its fundamental importance - the disk boundary layer is one of the simplest platforms for investigating the underlying structure of three-dimensional boundary layers - this cavity models more complex configurations relevant to rotating machinery. Large Eddy Simulation (LES) is performed using a Spectral Vanishing Viscosity (SVV) technique which is shown leading to stable discretizations without sacrificing the formal accuracy of the spectral approximation. Numerical results and velocity measurements have been favorably compared for a large range of rotational Reynolds numbers up to one million in an annular cavity of curvature parameter Rm=(b+a)/(b-a)=1.8 and of aspect ratio G=(b-a)/h=5, where a and b are respectively the inner and outer radii of the rotating disk and h is the interdisk spacing. In the detailed picture of the flow structure that emerges, the turbulence is mainly confined in the boundary layers including in the Stewartson layer along the external cylinder. For Reynolds numbers larger than 0.1 million, the stator boundary layer is turbulent over most of the cavity. On the other hand, the rotor layer becomes progressively turbulent from the outer radial locations although the rotating hub is shown to destabilize the inner part of the boundary layers. The isosurface maps of the Q-criterion reveal that the three-dimensional spiral arms observed in the unstable laminar regime evolve to more axisymmetric structures when turbulence occurs. At Re equal to one million, the flow is fully turbulent and the anisotropy invariant map highlights turbulence structuring, which can be either a ``cigar-shaped'' structuring aligned on the tangential direction or a ``pancake-shaped'' structuring depending on the axial location. The reduction of the structural parameter a1 (the ratio of the magnitude of the shear stress vector to twice the turbulence kinetic energy) under the typical limit 0.15, as well as the misalignment between the shear stress vector and the mean velocity gradient vector, highlight the three-dimensional nature of both rotor and stator boundary layers with a degree of three-dimensionality much higher than in the idealized system studied by Lygren and Andersson (2001-2006).
Eric Séverac, Sébastien Poncet, Eric Serre, Marie-Pierre Chauve. Large eddy simulation and measurements of turbulent enclosed rotor-stator flows. Physics of Fluids, 2007, 19 (8), pp.085113. ⟨10.1063/1.2759530⟩. ⟨hal-00170072⟩
Sébastien Poncet, Roland Schiestel. Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow. International Journal of Heat and Mass Transfer, 2006, 50, pp.1528-1544. ⟨10.1016/j.ijheatmasstransfer.2006.08.028⟩. ⟨hal-00170087⟩ Plus de détails...
The present study considers the numerical modeling of the turbulent flow in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Numerical predictions based on one-point statistical modeling using a low Reynolds number second-order full stress transport closure are compared with experimental data available in the literature. Considering small temperature differences, density variations can be here neglected which leads to dissociate the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial throughflow is well predicted compared to the velocity measurements performed at IRPHE (Poncet 2005) under isothermal conditions. When the shroud is heated, the effects of rotation and coolant outward throughflow on the heat transfer have been investigated and the numerical results are found to be in good agreement with the data of Sparrow and Goldstein (1976). Their results have been extended for a wide range of the Prandtl numbers. We have also considered the case of an open rotor-stator cavity with a radial inward throughflow with heat transfer along the stator, which corresponds to the experiment of Djaoui et al. (2001). Our results have been compared to both their temperature measurements and their asymptotic model with a close agreement between the different approaches, showing the efficiency of the second order modeling. An empirical correlation law is given to predict the averaged Nusselt number depending on the Reynolds and Prandtl numbers and on the coolant flowrate.
Sébastien Poncet, Roland Schiestel. Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow. International Journal of Heat and Mass Transfer, 2006, 50, pp.1528-1544. ⟨10.1016/j.ijheatmasstransfer.2006.08.028⟩. ⟨hal-00170087⟩
Journal: International Journal of Heat and Mass Transfer
Eric Serre, Sandrine Hugues, Emilia Crespo del Arco, Anthony Randriamampianina, Patrick Bontoux. Axisymmetric and three-dimensional instabilities in an Ekman boundary layer flow. International Journal of Heat and Fluid Flow, 2001, 22 (1), pp.82-93. ⟨hal-01023080⟩ Plus de détails...
Eric Serre, Sandrine Hugues, Emilia Crespo del Arco, Anthony Randriamampianina, Patrick Bontoux. Axisymmetric and three-dimensional instabilities in an Ekman boundary layer flow. International Journal of Heat and Fluid Flow, 2001, 22 (1), pp.82-93. ⟨hal-01023080⟩
Journal: International Journal of Heat and Fluid Flow
