It is very complex to calculate the aerodynamic drag of high-speed train running in railway tunnel with multi -shafts . And the difficulty is to calculate the velocity of piston wind.是什么意思_It is very complex to calculate the aerodynamic drag of high-speed train running in railway tunnel with multi -shafts . And the difficulty is to calculate the velocity of piston wind.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句