液力缓速器部分充液流场大涡模拟及特性预测

利用CFD平台的大涡模拟法和滑动网格法对液力缓速器内部气液两相流动进行三维瞬态数值模拟,将混合模型与欧拉模型交替运用在其多相流模型中,得到速度场和压力场的分布特性,总结不同充液率下液力缓速器内流场结构的变化及两相体积分布情况.基于流场数值解计算了液力缓速器不同工况下的制动转矩,进而预测其性能,性能预测结果与试验结果吻合较好,误差在8％以内,表明流场计算是较准确的,其结果可用于液力缓速器的设计及其结构优化.

Large eddy simulation on internal flow field of hydraulic retarder and characteristics prediction

Based on the methods of large eddy simulation and sliding mesh in CFD software,the three-dimension transient numerical simulation of two-phase flow in the hydraulic retarder was performed,in which mixture model and Eulerian model were used alternately,and the distribution characteristics of velocity and pressure were obtained.Through analyzing the velocity and pressure fields,the change of internal flow field structure and the distribution of the two-phase flow at different filling rates were summarized.The braking torque in each working condition was figured out based on the numerical solution of the 3-D flow field,and the results are in good agreement with the experiments.The maximum deviation is 8%,which indicates the accuracy of numerical calculation methods,and the numerical results will greatly contribute to designing a hydraulic retarder and optimizing the structure.