Simulation On Flow Filed Of Lubrication System And Temperature Filed Of A Wet Dual Clutch

The heat generated by the relative motion between the friction and steel plate will lead to the temperature rise of friction pair during the operating of a wet clutch.If the generated heat cannot be taken away by cooling oil in time,the working performance of friction pair will be degraded and thermal failure is even caused.In order to ensure the long-term reliable operation of a clutch,it is necessary to study the influence of the cooling oil passage structure on the flow characteristics of oil and then predict the temperature distribution of a clutch accurately so that a cooling system can be designed appropriately.In this paper,the flow field and temperature field of a wet dual clutch are simulated based on the FLUENT software to solve the problem of the deformation and ablation of friction pair due to its overheating under a condition of low speed and high torque.The main work and conclusions are as follows:1.Research on the flow field characteristics of cooling oil between a friction pair.Based on the FLUENT software,the flow field of cooling oil between a friction pair is simulated and analyzed,and the influence of groove structural parameters on the flow filed characteristics of cooling oil between a friction pair under clutch engagement and disengagement conditions is studied.The results show that the structural parameters of radial groove have a great influence on the cooling oil flow field between friction and steel plate.When the inclination direction of groove is opposite to the rotation direction of friction pair,the groove inclination angle has a great influence on oil flow field between fiction pair.The deeper and wider the radial groove is,the greater influence of groove on the oil flow field in the gap between friction pair.The structural parameters of circumferential groove have little effect on the flow field between friction pair,but when the groove depth is large,it has a certain influence on the cooling oil flow field in radial groove.2.Simulation of cooling oil flow field characteristics of a wet dual clutch.According to the simulation results of the flow field,the clutch cooling oil passage is reasonably simplified,and the flow field characteristics of cooling oil under three typical conditions are simulated based on the FLUENT software.The results show that the rotating speed has a small influence on the pressure distribution of the clutch cooling oil passage,but has a great influence on the pressure value.The higher the rotating speed,the greater the absolute pressure value and pressure difference of internal and external oil passage.The rotating speed has little effect on the velocity distribution of cooling oil,but the velocity value rises with the increase of rotating speed.3.Research on the heat flow distribution of a friction pair.Based on the FLUENT software,the temperature field of a friction pair is simulated,and the influence of structural parameters such as contact area of friction pair,thickness of steel plate and number of grooves on the heat flow distribution between the friction and steel plate is analyzed.The results show that the contact area and the groove number have little effect on the heat flow distribution of a friction pair,but with the increase of steel plate thickness,the heat flux flowing into the friction plate decreases.4.Temperature field simulation of a wet dual clutch.Firstly,the thermal boundary method is used to simulate the temperature field of a friction pair,and the influence of small grooves on the temperature filed of friction pair is analyzed.On this basis,the friction plate structure is simplified and the fluid-solid coupling simulation model of clutch is established,then the temperature field of the clutch under three typical working conditions is simulated.The results show that under low speed and large torque working condition,the temperature of clutch is the highest,and the highest temperature of steel and friction plate are 152.8℃ and 154.5 ℃ respectively,which are in the allowable working temperature range of steel and friction plate so that the clutch can be well cooled under the three working conditions.The simulation results are close to the experimental test results,and the maximum relative error between simulation value and test result is 4.9%.