Lateral aerodynamic performance and speed limits of double-deck container vehicles with different structures

摘要

Based on 3D,steady N-S equations and k-ε turbulence model,Fluent was employed to do numerical simulation for lateral aerodynamic performance of 6-axis X2K double-deck container trains with two different loading forms,and speed limits of the freight trains were studied.The result indicates that under wind environment:1) As for vehicles without and with cross-loaded structure,aero-pressure on the former is bigger,but air velocity around the latter is larger;2) When sideslip angle θ=0°,the airflow is symmetry about train vertical axis;when θ>0°,the airflow is detached at the top of vehicles,and the air velocity increases above the separated line but decreases below it;3) With θ increasing,the lateral force on the mid vehicle firstly increases but decreases as θ=75°;4) When the 6-axis X2K flat car loads empty boxes of a 40 ft and a 48 ft at 120 km/h,the overturning wind speed is 25.19 m/s,and the train should be stopped under the 12th grade wind speed.