Research On Velocity Field Distribution And Flow Reduction Inside Flow Channel Of Torque Converter

The key to improve the performance and efficiency of the Torque converter is to deeplyunderstand the phenomenon of fluid flow within the structure. In this paper, the flow fieldof a certain torque converter was computed under different speed ratios by CFD numericalsimulation and tested by Laser Doppler Anemometry (LDA), then reduce the flow order byPOD method to simplify the flow structure.Firstly, build geometric model of the torque converter and do the steady state simulationby CFD software. Analyze the overall distribution of the flow field inside the torqueconverter from the result of the simulation so as to determine the presence of the secondaryflow in the flow channel, such as the turbulence, off the flow and reflow phenomenon.Secondly, by setting the transient simulation timesteps reasonably and acquire thetransient flow speed data of the torque converter. Then test the flow speed data of the flowfield inside the torque converter with the open window by (LDA).This test mainly obtainthe speed of different faces of the pump domain. Next, compare the simulation result withthe test result in order to prove CFD simulation is accurate enough to study the transientflow of torque converter.Finally, research on the static and dynamic interference effect between the impeller basedon the results of transient CFD analysis. Then study the impact on the flow field and theimpeller blade pressure due to the different positions between pump and turbine impeller soas to find the distribution of the transient flow field. Use the proper orthogonaldecomposition (POD) method to reduce the order of transient flow deconstruction andrebuild the velocity field by small amount number of items. By analyzing the intrinsic sizeof the energy to acquire main modes of flow structure and analyze the main structure of theflow field. In result, obtain the major mode structure and the pulsating flow fielddistribution and reveal flow field changes the torque converter in the actual engineeringwork.