| When a high-speed train is running,it will form a train wind around it.When there is snow on the ground and track,train wind will draw some snow particles in the snow into the air flow field,which will accumulate on the components of the train bogie easily.The snow accumulation in the bogie area will affect the effect of vibration reduction,braking and steering of the bogie,and reduce the stability and safety of the train during operation.At present,in the numerical study of snow accumulation in the bogie area of high-speed train,the mechanism of snow accumulation in the bogie area and the factors affecting the snow accumulation in the bogie area are lacking.In this paper,the aerodynamic characteristics and snow accumulation characteristics of the bogie are studied by numerical calculation.At the same time,the influence of different factors on the snow accumulation in the bogie area was explored.In order to study the snow protection performance,different snow protection structures are placed at the front and rear end plates of the bogie cabin.The main research contents and conclusions are as follows:(1)The aerodynamic calculation model of three-car marshalling high-speed train is established.Three-dimensional incompressible Navier-Stokes equations and Realizable kepsilon turbulence model are used to study the aerodynamic characteristics of the bogie region.The aerodynamic characteristics in the bogie region are analyzed.The results show that the streamlines in the bogie area are complex,the flow velocity is low,and the snow particles are easy to deposit.(2)Based on the discrete phase model,researching the motion of snowstorm at the bottom of a train.Injections were set on the ground to study the starting and movement of snow particles under the action of train wind and analyze the concentration distribution of snow particles at the bottom of the train.The results show that the snow particles enter the bogie area with the eddy current moving upward,and are easy to form deposits in the rear of the bogie.(3)To explore the influence of different factors on the snow accumulation in the bogie area.Firstly,a snow deposition model was established based on Trenker snow deposition criterion to study the influence of critical snow deposition Angle and critical shear wind speed on the snow accumulation in the bogie area.Secondly,the influence of snow density,particle size and initial conditions on snow accumulation in the bogie area is studied.Finally,the variation law of snow accumulation characteristics of bogie under different factors is analyzed.The results show that the influence of snow density,particle size and initial conditions on the snow accumulation of the bogie is stronger than the critical deposition Angle of snow and the critical shear wind speed.(4)In order to alleviate the snow accumulation in the bogie area,snow protection structures were set at the front and rear end plates of the bogie compartment.Firstly,the aerodynamic characteristics of the bogie area under different snow protection structures are analyzed.Then the influence of snow protection structure on the characteristics of snow in the bogie area is studied.Finally,the optimal snow protection structure is given according to the research results of snow protection in this subject.The results show that the 30 mm deflector has the best snow control effect,which can reduce the snow deposition number in the bogie area by 95.51%.(5)The aerodynamic characteristics and snow accumulation characteristics of bogie under cross wind are studied.Firstly,the aerodynamic characteristics of train and bogie under cross wind are studied and analyzed.Then,the influence of cross wind speed and wind direction on aerodynamic drag of train and bogie was explored,and the variation law of aerodynamic drag of train and bogie was analyzed under different cross wind speed and wind direction.Finally,the snow protection effect of 25 mm deflector,right Angle spoiler and obtuse Angle spoiler under cross wind is studied.The results show that the right-Angle spoiler has the best effect on the snow accumulation of the bogie under cross wind,which can reduce the snow deposition number by 57.72%.In this paper,the aerodynamic characteristics,snow accumulation characteristics and snow protection optimization of the bogie are studied.Relevant research methods and results can provide theoretical guidance and technical support for the snow accumulation of the bogie and the optimization of snow accumulation. |
