Simulation Optimization Of The Heat Dissipation Of The Brake Disc Of High Speed Train

The brake disc of a high speed train is an important brake part.Through the friction braking of the brake disc and the brake,the kinetic energy of the train movement is converted into heat energy,and the train is decelerated or stopped by contact with the air fluid.In braking,a lot of heat will be produced.As the heat absorbed by the brake disc is much more than the heat absorbed by the brake disc,the temperature of the brake disc increases rapidly,and the temperature gradient will produce the temperature.The thermal expansion of the brake disc is the cause of the heat induced stress.Therefore,studying the temperature field of the brake disc and improving the cooling performance of the brake disc is of great practical significance for the safe operation of the train.Air convection heat transfer is the most important energy exchange mode for brake discs.By adjusting the structure and distribution of the fin in the brake disc,the flow state of the air inside the brake disc is changed,the heat dissipation area of the interior is increased and the overall heat dissipation capacity is increased.Based on the CFD technology,the heat dissipation fin of the brake disc of the high speed train is studied and analyzed.The first step is to consider the effect of air flow on the heat dissipation of fin with different structures.The commonly used CAD 3D modeling software is designed to design a new cooling fin structure,and the actual size of the existing brake disc is selected for entity construction.As the force of brake disc and sluice are both axisymmetric,in order to reduce the scale of calculation using 1/12 model,set boundary conditions and initial conditions,define the symmetry surface to restore the whole model.The brake disc of various different structures is simulated one by one,and the motion law and temperature distribution law of the air fluid inside the brake disc are obtained.The air flow field and the temperature field are summed up,and the preliminary simulation analysis is carried out.The second step is to simulate the transient heat dissipation capacity of the whole disc in the first selected three brake disc models,and verify that the simulation adds the effect of solid rotation,which can better reduce the motion of the brake disc during the braking process.Speed change function is set according to the gradual slowing down of braking speed.Considering the coupling interface between the air fluid and the brake disc solid,a peripheral air coating is added to make a smooth transition of the grid,and the mesh refinement is only used for the contact surface.After solving the results,a variety of analysis tools are used to observe the related parameters related to the change of thermal energy in the braking process,and then the heat dissipation capacity of the selected model is tested and the appropriate fin shape is determined.The third step is to study the heat dissipation capacity of the brake disc under the actual working condition of the brake disc,and use the method of energy conversion to determine the heat flux density on the two friction rings of the brake disc.According to the actual running state of the train,the quality of the whole vehicle and the way of replacing the heat source are added to the same state as the actual effect.The factors that affect the heat dissipation capacity are used to improve the final optimization.The results show that the fin plate fin heat dissipation is stronger than the columnar fin,and the wedge plate is better than the direct plate.