本研究系利用回應表面法在考慮非穩態空氣動力與尾流動力環境下，尋求直昇機在不同的飛行狀態下，滿足旋翼葉片最大升力要求之最小輸出功率。回應表面法是一種建立近似系統整體反應的方法，利用在設計空間中不同觀察點建構出近似函數。由於該近似函數較為簡單，吾人可以很容易地運用最佳化方法快速得到一近似解，大幅降低系統分析所需的時間。 本研究結合了旋翼的空氣動力及尾流動力之耦合系統，並選用Peters的尾流動力理論作為非穩態空氣動力環境模擬。將應用回應表面法於旋翼葉片最佳化設計上，並且採用增加實驗觀察點的數目、縮小設計空間等技巧尋找出最佳設計的值。由於同時考慮弦長與扭角之設計，使得設計變數倍增也增加問題之複雜性。本研究將利用迴歸分析的優點，確保設計變數和回應值之間的關聯性。 在範例中將考量貝爾UH-1H 直昇機在各種不同飛行狀態時，主旋翼葉片之最佳化設計及性能分析，並與文獻之結果相比較，相信本研究方法對直昇機旋翼葉片的設計有其重大的貢獻。 This study presents an application of Response Surface Methodology (RSM) for a helicopter rotor blade design through an unsteady wake dynamic and aerodynamic coupling system. The purpose of this study is to obtain the optimal configuration of the blade which to minimize the power output and also maintain lift force in a mission. RSM is a method of constructing system behavior, approximate function based on results calculated at various points in the design space. Therefore, the computational time can be saved by using the approximate function to obtain the solution by optimum method.
The unsteady wake dynamic system is simulated by the Peters finite state inflow theory. The blade element theory and lifting-line theory are used to formulate the aerodynamic force for a blade. The technique of reducing the design space was used to achieve the best approximation efficiently. The chord length and twist angle will be implemented as design variables simultaneously. To ensure the relationship between design variables and responses, the advantage of RSM can be used in this study.
The optimum design and performance analysis of BELL UH-1H helicopter will be discussed in the numerical example. Finally, this study will compare those results with other references, which demonstrate the advantages and feasibility of the RSM and optimum method of helicopter structural design.
