In order to study the flow loss in the leakage area of a hydrodynamic torque converter and how leakage flow influences the overall performances, numerical simulation of a hydrodynamic torque converter considering flow loss in the leakage area was carried out. It is found that the prediction accuracy of torque ratio and capacity factor is improved by 3.1% and 4.6% separately when considering the leakage area. The simulation results show that with the increase of the speed ratio, the main circulating flow and leakage flow decrease gradually, and the leakage flow accounts for about 4% of the total flow of torque converter. There is a secondary flow phenomenon in leakage area. Vortex and the sudden change of flow cross section result in the loss of the leakage area, and the flow loss at low speed ratio is higher than that at high speed ratio. Compared to the simulation model without leakage area, the outflow of leakage area can reduce the eddy viscosity at the pump inlet. © 2018, Editorial Board of Journal of Huazhong University of Science and Technology. All right reserved.
