湿式クラッチにおける気液二相流の数値解析

抄録

In this study, we focus on wet clutches, which are widely used in automobile transmissions, and compare the behavior of gas-liquid two-phase flow of oil and air between narrow flat plates simulating wet clutches by experiment and numerical analysis to clarify the mechanism of drag torque generation because of fluid friction caused by the increase in rotation speed between clutch plates. In the numerical analysis, the VOF (Volume of Fluid) method is used to track the gas-liquid two-phase interface, and the SST k-omega, which solves the two-equation RANS shear stress transport equation, is also used to incorporate turbulent flow phenomena. In this paper, the causal relationship between the vortex generation on the surface distribution and the drag torque will be rigorously checked. In addition, the behavior of the drag torque curve and the interface distribution at 50[℃] and 80[℃] were clarified by using temperature as a factor. As a result, the drag torque curve could not be reproduced perfectly, but it was found that the drag peak occurred earlier in the experiment than in the analysis at every 200 [rpm] of the rotation speed with and without temperature change. In addition, the downward slope in the gas-liquid two-phase region could be reproduced because the air mixture after the drag peak was well removed. In addition, it was found that when the interface was at 50[℃], the oil was cut cleanly from the periphery, while at 80[℃], the oil was cut in a spiral shape due to the decrease in oil viscosity, and air was mixed in.