Simulation Of The Action Effect Of Wind-driven Rain On High-speed Moving Passenger Vehicle

In this paper, FLUENT discrete model initialization solving conditions are deduced by raindrop spectrum and raindrop end velocity formula, the systematic method of a rainfall process numerical simulation is established. Then the double equation turbulent model and discrete phase model are used to solve the initialization solving conditions. Based on this, the effect of different cross wind speed, different rainfall intensity and different velocity on high-speed moving passenger vehicle is analyzed through the analysis of force, stress nephograms, figures of streamline and raindrop concentration. The conclusions are as follow:Conditions of no effect of the cross wind:The first, the air close to the train surface will move at the speed of the tain because of the effect of friction. The rain drops will be stretched after they land to the surface of the carriage, and because of this, the drag force on the carriage becomes bigger. The drag force on the carriage increasing as the rain becomes heavier. The second, the pressure on the lower part of the carriage increasing as the rain becomes heavier under the effect of the movement of the air around the carriage, relatively, the pressure on the top of the carriage increase smaller, as the reason above, the lift force on the carriage becomes bigger.Conditions under the influence of the cross wind:The first, the rain drops of different diameter has a motion of different distance along the horizontal direction before they fall down to the ground when the speed of the cross wind is certain and the distance becomes longer when the speed of the cross wind becomes bigger. The second, the rain drops under the effect of cross wind crashed on to the surface of the carriage and then splashed, which change the roughness and smoothness of the surface of the carriage, this lead to that the drag force increase as the speed of the cross wind becomes bigger and diminish as the rain becomes heavier. The lift force and upsetting moment on the carriage are quite the contrary. The third, the drag force, lift force and moment on the carriage are all increase as the train runs faster under the effect of rain fall and cross wind. The last, vehicle overturn stability will be further reduced under the effect of cross wind and heavy rain than the condition of only cross wind, further speed limit measures should be taken at the basis of the original speed limit standard.