The hydrodynamic torque converter (HTC) is extensively employed as the key transmission component in transport vehicles and construction machinery due to its excellent performance in torque multiplication, vibration isolation, and stepless speed variation. Engineering vehicles frequently operate under complicated working conditions, such as climbing, reversing, trailer starting, and downhill driving. Nevertheless, current research on the internal flow and external characteristics of HTC under reverse conditions (climbing and sliding) and overrunning conditions (trailer starting) is relatively scarce. To address the limitations of existing studies, computational fluid dynamics (CFD) is employed to establish a full-flow passage model of HTC. Flow field evolution under various working conditions is analyzed in terms of pressure, velocity, and temperature, revealing the flow mechanism. In addition, finite element analysis is used to construct a strength model for HTC impellers, and the deformation law of the impeller shell is summarized based on stress. Bench tests are conducted to obtain external hydrodynamic characteristics under traction conditions, and simulation results are validated against experimental data. The test results show that the maximum error of the pump torque coefficient (λB) is 7.52%, less than 10%, the maximum error of the torque ratio (K) is 8.48%, less than 10%, and the maximum error of the efficiency (η) is 8.48%, less than 10%, which proves the accuracy and reliability of the CFD method. This research provides an effective technical approach for the design and optimization of the cascade system and the impeller structure of high-power-density HTC.
Ran et al. (Fri,) studied this question.