近年來,溫室效應和全球暖化的影響越來越嚴重,造成降雨率持續攀升打破各地紀錄。直升機或旋翼機也是飛機的一種,是利用兩片或是多片的水平主旋翼葉片旋轉推動以產生升力,有懸停和垂直起降特性,利於台灣極端溫差天氣的救災狀況,因而在空中勤務總隊裡廣泛使用,所以大雨中直升機的性能探討分析和發展值得我們深入研究。隨著研究大雨的物理現象,我們利用CFD方法成功估算出標準主旋翼葉片受到大雨時所造成的不利影響現象,因此建議直升機飛行員應該藉此訊息事先加以防範,或增加訓練科目,相信本研究結論能為直升機在惡劣天氣下救援能有所幫助。 In recent years, the greenhouse and global warming effects are becoming more and more severe, that partially explains why rainfall rates keep breaking record in all parts of the world. In general, helicopter or rotorcraft is an aircraft that is lifted and propelled by one or more horizontal main rotors, and it can take off and land vertically. Currently, helicopter has widespread utilization by air rescue unit in Taiwan during disaster situation under extreme weather situations. For this reason the understanding and improvement of helicopters under heavy rain condition is the main theme of this research. With our understanding of heavy rain physics, a CFD tool has first been developed and successfully tested on the standard helicopter blade. Once the heavy rain droplets are added, it is observed that rainfall indeed will decrease the total lift and might induce some detrimental effects on the main rotor blades performance. Therefore, it is highly recommended that every helicopter pilot should be aware of the information gained in this work and accepts extensive training in simulating heavy rain situations.