Numerical Simulation Research Of The Snow And Ice Accumulation In The Bogie Region Of A High-speed Train

Snow and ice accretion in the bogie regions of high-speed train seriously affects the running quality and threatens the running safety.When the train runs in the snow environment in winter,the snow particles on the track will be rolled up and entering the bogie regions.The snow particles will be deposited on many important parts under the action of viscosity or gravity.Due to the heat dissipation of the motors and the friction heat of the brake discs during the train operation,the snow deposited in the bogie regions melt and congeal into ice.The freezing of bogie parts will have adverse effects on the braking of the train and the dynamic characteristics of the bogies.In this thesis,the similarity criterion of snow movement,water spray from brake discs and ice accretion in the problem of snow and ice accretion in the bogie region of high-speed train are studied.The main contents and conclusions are as follows:(1)The similarity criterion of snow particles movement in high-speed train bogie regions was established,and verified by numerical simulation.The results show that the paths of snow particles entering the bogie regions is similar under multi-dimensional scale based on similarity criterion.The snow particles near the bogie surfaces are mainly in,the front and rear brake devices,both sides of the vertical shock absorbers and anti-snake shock absorbers,the air springs and traction rods which at bogie middle areas,anti-rolling torsion bars and axle box devices.The snow particles near the bogie cavity surfaces are mainly distributed in the rear end plate,the upper part of the front plate and the both sides plate.(2)The bogie brake disc spray simulation method was established based on discrete phase model,and verified based on the independent wheel spray test results.This method and the liquid film model were used to study the movement of snow water sprayed by the brake discs in the bogie regions under different operating speeds.The deposition of snow water on the bogie surfaces and bogie cavity was analyzed.The results show that the thicker liquid film on the bogie surfaces is mainly distributed in the front and rear brake devices,the air springs area near the traction rods,the middle area and the bottom of the frame,the surfaces of bolster and traction rods near the rear wheel,etc.The liquid film mass on the front and rear brake devices accounts for more than 60% of the total liquid film mass on the bogie surfaces.The thicker liquid film on the surfaces of the bogie cavity is mainly distributed in the area near the brake discs.(3)The ice accretion of the motor bogie and the trailer bogie in the wind tunnel was studied,and the numerical simulation results were compared with the test results,which verified the feasibility and accuracy of the ice accretion simulation.The results show that when the influence of large water droplets and sputtering water on the ice accretion in the bogie region is not taken into account,the difference between the numerical results of the motor bogie and the experimental results is about 13%,and the difference between the numerical results of the trailer bogie and the experimental results is about 22%.(4)The quasi-transient method is used to simulate the icing process in the trailer bogie region of high-speed train.The characteristics of ice accumulation in the bogie region were studied.The results show that the ice in the trailer bogie region is mainly distributed in the bottom windward surfaces(the bottom of the frame,the bottom of the front and rear brake devices),the vertical shock absorbers and anti-snake shock absorbers on both sides of the bogie,the rear brake device of the bogie,the upper surface of the bolster and the front and rear axle boxs.The ice mass of bogie components from large to small is frame,bolster,rear brake device,air springs,shock absorbers on both sides,front brake device and traction rods.