航空湿式离合器接合过程中摩擦副间瞬态流场特性分析

Analysis of transient flow field characteristics between friction pairs during engagement of aviation wet clutch

以航空湿式离合器为研究对象,通过数值仿真得出摩擦片输出转速曲线和对偶钢片轴向移动曲线,采用最小二乘法拟合出输出转速曲线公式和钢片轴向移动公式,获得接合过程中时变的摩擦片输出转速和钢片轴向移动位移。基于计算流体动力学(CFD)方法,运用Fluent仿真技术,采用动网格方法,对轴心供油冷却方式下摩擦副的不同接合时间下的瞬态流场进行仿真分析,研究该润滑方式下瞬态油液的速度分布规律和压力分布规律。研究结果表明:摩擦副半径越大处,油液流速越大,润滑油在油液离心力的作用下,高速排出,部分油液不断被搅动,再次进入摩擦副片间润滑摩擦副;在该轴心润滑方式下,随着接合时间增大,油液所受的油膜承载力越大,油压分布越均匀,接合面的油压几乎呈对称分布,润滑效果好。

A numerical model was developed to analyze the transient flow field characteristics of the wet clutch.The output speed curve of the friction plate and the axial movement curve of the steel plate were obtained and the formulas were gotten by the least square fitting method.The transient flow field of the friction pair of the axial oil supply cooling mode at different engagement times were simulated and analyzed based on the computational fluid dynamics(CFD)method,using fluent simulation technology and the dynamic grid method.The speed distribution law and pressure distribution law of the transient oil were studied.The results show that the greater radius of the friction pair is,the greater the flow rate of the oil will be.The lubricating oil is discharged at a high speed under the action of the centrifugal force of the oil,and part of the oil is continuously agitated to lubricate.As the engaging time increases,the bearing capacity of the oil film becomes larger and the oil pressure distribution becomes more uniform.The oil pressure on the joint surface is almost symmetrically distributed with good lubrication effect.