The Study On The Impact Of The Setting Of High-speed Railway Bridge's Wind Barrier On The Train And Main Beam's Aerodynamic Performance

At present, China's high speed rail is in a period of rapid development. The faster the train travels, the greater impact the side wind has on the travelling train. With the help of FLUENT software, this thesis, adopting the method of three-dimensional numerical simulation, makes a study of the impact of setting high-speed railway bridge's wind barrier on the train-main beam's aerodynamic performance to ensure the safety of the travelling high-speed train.This thesis calculates the train and main beam's aerodynamic coefficients under all situations using static mesh model, discussing respectively the impact of bridge pier, the height of wind barrier, the train's horizontal position on the bridge, the wind barrier's ventilation rate and the wind angle on the train and main beam's aerodynamic performance. Results show that the bridge pier's impact on the train's aerodynamic coefficient is little and that on the main beam's impact is stable; with the increase of the height of wind barrier, the train's aerodynamic coefficient is decreasing while the main beam's aerodynamic coefficient is increasing; when the train is on different horizontal positions, upwind,the up train's aerodynamic coefficients are greater than or close to those of backwind,the down train; with the increase of the wind barrier's ventilation rate, the train's aerodynamic coefficient gradually increases, the main beam's drag coefficient decreases, the lift coefficient increases and the torque coefficient stably increases; in general, with the increase of wind angle, the train's aerodynamic coefficient is on a trend of increase and the main beam's drag coefficient, the torque coefficient also increases.This thesis simulates the train's travelling state on the bridge using the dynamic mesh model, making an analysis of the impact of wind barrier's height, the ventilation rate and the wind angle on the train's aerodynamic coefficient. Results show that the train's aerodynamic coefficient decreases with the increase of wind barrier's height and increases with the increase of the wind angle. With the criteria of stati cpercent of wheel load, this thesis concludes that it is reasonable to set wind barriers of 4m height and 30% ventilation. The main beam's aerodynamic coefficient does not change with wind angle.This thesis calculates the travelling train's critical speed in different wind speeds by use of VSI program according to the train and main beam's aerodynamic coefficient in different wind angles and compares it with the train's critical speed without wind barrier. The result shows that setting wind barrier can significantly increase the train's critical speed.