Research On An MPV Disc Brake's Heat Dissipation Performance Based On Fluid-Solid-Thermal Coupling

To improve the disc brake's heat dissipation performance makes contributions to improving the anti-heat fade performance and the safety of automobiles driving.In this paper,Fluid-Solid-Thermal coupling method was introduced to study the disc brake's heat dissipation performance.This research mainly contains: the establishment of disc brake's Fluid-Solid-Thermal coupling model under vehicle model,the analysis of numerical simulation results and road experiments,and the influence of drilling design on disc brake's heat dissipation performance.In the part of building Fluid-Solid-Heat coupling model,the disc brake's Fluid-Solid-Thermal coupling model was constructed under vehicle model for the purpose of heat dissipation process' s numerical simulation under emergency braking condition.Thereinto,the fluid part focused on the realization of the rotating wheel flow field,the transient change of vehicle external flow field under emergency braking conditions and air's physical properties changing with temperature.The solid part focused on the realization of the thermal energy conversion caused by friction on disk brake's working surface under emergency braking conditions,the heat conduction in brake disc and brake disc's material properties changing with temperature.STAR-CCM+ and ABAQUS were used as fluid and solid solver respectively.The surface of brake disc was taken as the coupling boundary.The fluid and solid regions were coupled in the way of independent calculation and boundary coupling.With this,the disc brake's Fluid-Solid-Thermal coupling model was established.In the part of result analysis and road experiment,the temperature distribution,flow field characteristics and heat flux distribution of brake disc at each moment were analyzed.The variation and distribution characteristics of temperature,flow field and heat flux were summarized.The heat dissipation process of the brake disc was explored.The conclusion was obtained: temperature difference and air velocity are the main factors affecting the heat dissipation efficiency of the brake disc.The established Fluid-Solid-Thermal coupling model was verified by road experiment.The results show that: the numerical simulation results were in good agreement with the road experiment results,and the errors were less than 9%,which proved the accuracy of the Fluid-Solid-Thermal coupling model.In the part of the influence of brake disc's structure improvement on heat dissipation performance,the brake disc's structure was improved by drilling design.The influence of drilling density,drilling location and drilling arrangement angle on heat dissipation performance of brake disc was studied by orthogonal experimental design.Three factors and three levels of orthogonal experimental were arranged reasonably according to the orthogonal table,and the corresponding numerical simulation was completed.Taking the average temperature of the main temperature rising domain of the brake disc as the indicator for evaluating the heat dissipation performance,orthogonal experimental results were analyzed by range analysis table,and the rank and rule of influence of each factor on heat dissipation performance were obtained.The influence degree was sorted from big to small: drilling density greater,drilling arrangement,drilling distribution position.From the temperature distribution,flow field characteristics and heat flux distribution,the principle of improving the heat dissipation performance of brake disc by the drilling design was studied.In this paper,by introducing the Fluid-Solid-Thermal coupling method,the heat dissipation process of disc brake in vehicle was reproduced by numerical simulation as realistic as possible.The accuracy of the Fluid-Solid-Thermal coupling method in the study of heat dissipation process of disc brake was verified by road experiments.The influence of brake disc's structure improvement on heat dissipation performance and principle were studied.It has important guiding significance and practical value for the development and production of vehicle disc brake with good heat dissipation performance.