In this study, we are interested to the turbulent mixed convection in a ventilated enclosure. A heat source is placed at the middle of the enclosure that's equipped with two openings; one is located at the lower left corner and the other located in the upper right corner. The width of the opening "h" represents 1/5 of the side of the cavity. The walls of the cavity are maintained adiabatic. The temperature of the heat source Th is higher than the room temperature. The width of the heat source "D" is equal to the opening width "h" (D = h). The governing equations of turbulent mixed flow convection in the cavity are solved using finite volumes method. A model k-ε of two-equation was used for closure the equations of turbulent regimes. The Grashof number is set constant (Gr = 10 9 ) and the Reynolds number (Re) varied such that the Richardson number (Ri) takes the values : 0.01, 0.05, 0.1, 1, 2, 5, 10, 20 and 30 (Ri = Gr / Re 2 ). The effects of flow thermal, dynamic parameters, the geometry and heat source dimensions are presented and discussed.