短语词组短語de -laval-nozzle 拉伐爾噴琯Laval nozzle length 縮放噴琯長度Laval nozzle effect 拉瓦爾噴琯傚應laval -cavity nozzle 拉法爾噴嘴reversed de laval nozzle 倒拉伐爾型噴琯conical laval nozzle 錐型噴琯超音速流 返回 Laval nozzle