Comparison influence of bilateral fluid pressure on fluid-solid coupling model of hydraulic torque converter structure

Abstract

The main purpose of this paper is to explore the importance of external flow field circulation of hydraulic torque converter assembly in analysis. Compared with simply considering the internal flow field characteristics, it has influence on the internal flow field analysis, external characteristics and structural stress of hydraulic torque converter assembly. This paper models the flow path of the torque converter with different Schemes, the flow field pressures distribution on the impeller are analysed using computational fluid dynamics method (CFD). Scheme A adopts the traditional idea, which simply considering the influence of internal flow field on the performance. Scheme B contacts the external flow field especially including the auxiliary cavity, and comprehensively studies the influence of it on the performance. The results show that with the addition of an auxiliary chamber, the overall flow field pressure of the torque converter is lower than that without the auxiliary chamber. The external characteristics of the torque converter assembly were tested on experiment equipment, which has been verified that the CFD simulation results with the addition of the auxiliary chamber are closer to the experiment data, proving the accuracy of the method for the pressure simulation of flow field. On this basis, the stresses and deformations of the torque converter considering the auxiliary fluid chamber are compared and analysed in relation to the displacement limitations of the impellers. The results show that the maximum stress in the turbine is reduced by 57%–12% compared to the scheme A without considering the auxiliary fluid. In the case of special operating condition, the maximum stress was 137.06 MPa before considering the auxiliary fluid, while the maximum stress was 60.625 MPa after considering the auxiliary fluid, and the reduction is 57%. The effects of input speed, speed ratio and impeller structure on the stress and deformation were also analysed, and the results show that the impeller structure and input speed have a great influence on the stress and deformation.