Abstract:In order to improve the accuracy of traditional turbulence simulation calculation models of hydraulic retarder, the improved two-equation turbulence model of SST-Kω is used to numerical simulate the turbulent flow of hydraulic retarder as the research object named THB40, under different filling ratio and different velocity with gas-liquid two-phase whole flow in the CFX14.5, aimed at the flow characteristics of strong rotation, multi wall and large curvature. The calculation results of braking torque showed that the torque was increased as the velocity increased when the filling ratio was 95%, decreased as the velocity increased when the filling ratio was 38%. This was consistent with the results of the bench test, the maximum error between computer fluid dynamics(CFD) and bench test was 3.6%. Compared with the traditional turbulence models, the precision of improved SST--Kω- turbulence model was raised about 20%, and the running time was saved by nearly 50%, which means that the turbulence model of improved SST-Kω is more suitable for simulating turbulent flow of hydraulic retarder. The research results provide an accurate and highly efficient reference calculation model of CFD to deeply study the breaking mechanism of hydraulic retarder.