The influence of density ratio on the characteristic frequency of coherent structure on the centreline of low Re number free round jet flow has been investigated with Dual PDA.是什么意思_The influence of density ratio on the characteristic frequency of coherent structure on the centreline of low Re number free round jet flow has been investigated with Dual PDA.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句