Abstarct: The evolution of the entrainment coefficient β of the rotating fluid in a rotor-stator cavity with an inward throughflow and pre-rotation is studied according to the flow parameters. This thesis describe a numerical study of flow in such a system .The Reynolds-avaraged Navier-Stokes equations in cylindrical polar coordinates were solved in primitive-variables using the finite-volume method , hybrid differencing and the SIMPLE pressure-correction scheme. The low Reynolds k-ε model has been used for numerical analysis. A simplified axisymmetric model has been used to study the effects of flow parameters on flow in this system. Measurements are obtained in water for a turbulent Batchelor type of flow with two separated boundary laxyers on the rotating and stationary disks.The computed results are compared with available measured data performed by S.Poncet,M.P.Chauve(2004)[1]. The results have good agreement with experimental data.