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.