液力变矩器泵轮内流场非定常流动现象研究

液力变矩器内部为复杂的三维非定常湍流流动,为分析变矩器泵轮内部三维非定常流动特性,建立液力变矩器非定常计算流体力学(Computational fluid dynamics,CFD)仿真分析模型,并通过激光多普勒测速(Laser Doppler anemometry,LDA)技术手段对该模型进行验证分析。研究泵轮转速800 r/min,速比为0.6工况下,不同涡轮和导轮位置,对于泵轮内流场非定常流动现象的影响。结果表明:该非定常CFD模型结果与LDA测试结果相吻合,且能够较为准确地反映泵轮内流场非定常流动状态,作为泵轮流场的上游,相对于涡轮对泵轮内部流动的影响,导轮对泵轮内流动状态的影响较大,并主要影响泵轮入口面附近。涡轮主要影响泵轮内流场中间面到出口面的尾流低速区,但影响幅度相对于导轮较小。

Research on Unsteady Flow Field of the Pump in Hydraulic Torque Converter

The flows in hydrodynamic torque converter are extremely unsteady and complicated 3D viscous and incompressible turbulences. The unsteady computational fluid dynamics (CFD) model of hydraulic torque converter (HTC) is established to study the unsteady flow field in the pump of the HTC due to the pump/stator and pump/turbine interaction, at the pump rotating speed of 800rpm, and the turbine/pump speed ratio of 0.6. The time-averaged CFD results obtained are compared with experimental data gathered using laser Doppler anemometry (LDA). The basic phenomena of the complex and highly unsteady flow inside the pump is presented and analyzed in detail. The results show that the upstream propagation influence of the stator on the pump flow field is stranger than that of the turbine, the effect of the stator on the pump is mainly on the inlet-plane to the mid-plane, the effect of the turbine on the pump is mainly on the low speed area from the mid-plane to outlet-plane.