Research On The Torque And Internal Flow Field Of Automobile Wet Clutch

The drag torque generated by the vehicle wet clutch causes the power loss of the powertrain.This paper studies the drag torque and the internal flow field of the wet clutch for the purpose of reducing the drag torque.In this paper,the fluid domain between a single pair of friction discs is taken as the research object.Considering the viscosity-temperature characteristics of the lubricating oil,a combination of mathematical modeling,numerical simulation and experimental research is used to study the influence mechanism of oil flow rate,friction disc rota ting speed and friction disc groove on the drag torque and the flow field between the discs and the relationship between the two.The influence of the oil physical properties,the physical environment and structure of the wet clutch on the drag torque during the test are illustrated.The paper analyzes the influence of the friction discstructure parameters on the drag torque and gives reasonable suggestions in combination with production for the friction disc structure improving.Firstly,the mathematical model and the computed fluid dynamics(CFD)model are established.The models are used to calculate the drag torque of the inner clutch of a certain type of wet double clutch.The CFD model value is consistent with the over all trend of the mathematical model value but there are a few differences.From the differences,the influence of the flow field characteristics on the drag torque and the fo rmation mechanism of the flow field characteristics between the discs are analyzed.Then the drag torque test is carried out.The relationship between the critical speed,the peak drag torque and the oil flow rate is in accordance with the mathematical model.The drag torque speed characteristics obtained by test is in good agreement with the CFD model.This proves the CFD model.Finally,the influence analysis of the friction discstructure parameters is carried out under the engineidle condition,and reasonable suggestions for structural optimization are given in combination with the relevant pe rformance and production practice.