湿式离合器对偶片间油气两相流动的数值模拟

湿式离合器高速旋转时内部形成的复杂油气两相流动会对离合器的性能产生影响,因而需要对湿式离合器内的两相流动特性展开研究。基于有限体积法,采用流体体积函数(Volume of fluid,VOF)多相流模型、RNG k-ε湍流模型,建立考虑径向沟槽影响的三维湿式离合器对偶片间油气两相流动模型。通过对流动模型中油气两相N-S方程进行数值求解,获得了湿式离合器对偶片间油气两相流动的流场分布特性,分析沟槽数量和转速对流场中油相分布及带排转矩的影响。结果表明:湿式离合器内部的润滑油分布是不均匀的,随沟槽的分布呈现出周期性变化,沟槽处润滑油油液体积分数最大;转速和沟槽数目的增加均会使对偶片间油液体积分数下降,影响湿式离合器内润滑油分布的不均匀性;沟槽总面积不变时,增加沟槽数量能使带排转矩最大值减小,最大转矩对应的转速提前。本研究为湿式离合器内部流场分析和带排转矩研究提供了一种新方法。

Numerical Investigation of the Air-oil Two-phase Flow inside a Wet Clutch

The air-oil two-phase flow inside a wet clutch impacts its performance. It is needed to study the two-phase flow characteristics inside the wet clutch. The air-oil two-phase flow model is established based on the finite volume method and RNG k-ε turbulence model. Through the numerical analysis of three-dimensional Navier-Stokes equations of the air-oil two-phase of lubricating medium inside a wet clutch, the flow field distribution of lubricant oil is obtained. The study is verified by compared with experimental data. The results show that the distribution of lubrication oil inside a wet clutch is not uniform. The oil volume fraction reaches the maximum in the groove. The average oil volume fraction increases with the increase of rotary speed and groove number. With the increasing of rotation speed, drag torque first increases, then decreases, and finally remains unchanged. In the same total groove area, the maximum drag torque decreases with the increase of groove number. The present study supplies a new method to the field analysis of lubricant oil and drag torque inside a wet clutch.