free-air flow的用法和樣例：
例句
- Propeller fans are used to move free air within a room or through channels having low frictional resistance.
螺旋槳式風(fēng)機通常用于房間內或通過(guò)風(fēng)道時(shí)移動(dòng)自由氣流時(shí)，產(chǎn)生微弱的摩擦阻力。 - This turbulence caused the flow pattern in the tunnel to be similar to the flow pattern in free air at a higher Reynolds number.
這種紊流使風(fēng)洞內的流譜與在較高的雷諾數下自由氣流中的流譜相似。
