A DCT With Underhood Cooling Circulatory System Simulation Analysis And Evaluation Research

Analyzing the thermal field of a transmission to predicting the temperature changes oftransmission lubricant oil effectively during the working process is significant to avoidoverheating of the oil which might result in failures of the transmission. This can also ensurethe normal operation of transmission and increase the service life of transmission.This study is working on an automatic transmission which was developed by a researchinstitute. The geometry of model is cleaned up and simplified by the pre-processing softwarenamed HYPERMESH, the meshes and boundary conditions are set by the GAMBIT, thesimulation process is solving by the FLUENT software.Firstly, the reasons for the heat of the transmission are analyzed according to the workingprinciple, types of its internal heat source and heat transfer path are also investigated. Thethermal power calculation formula is applied to calculate the power loss and heat value oftransimission.Then, a closed transmission cavity is created by simplifying the structures, inculding thebody case, the rotary member, the gears meshing and other internal structures of thetransmission. The whole CFD model of the transmission thermal system is created afterdefining the calculation model and boundary conditions and setting a monitor surface on thelocation of the oil pump inlet. The temperature of the monitor surface is regarded as thetransimission oil temperature of the3D simulstion. The transimission temperature distributionunder the six-speed high-speed condition and the low speed climbing condition is analyzed.Finally, the working principle of vehicle engine underhood cooling system is analyzedand the one-dimensional thermal network simulation model of vehicle cooling system,including the transimission oil cooler and the engine cooling system, is developed by usingthe FLOWMASRTER software. The temperature distrtibution of coolant and thermalcomponents is analyzed at the balance state of the cooling system. Whether the oil coolermeets the requirements of the system is checked according to the cooling effect of the coolingsystem and the cooling effect of cooling system is also evaluated. The results show that thetransmission oil cooler meet the cooling requirements of the relevant conditions under thehigh speed condition and the low speed climbing condition.