本研究係利用最佳準則法在考慮非穩態空氣動力環境下，以期設計出葉片最佳的弦長分佈值。此法必須滿足庫恩塔克必要條件，並能在一固定的推力限制下獲得最低輸出功率。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的尾流動力理論作爲非穩態空氣動力環境的模擬，且利用葉片元素理論及升趨泉理論推導出升力函數。本研究中將討論兩種截然不同的飛行狀態：滯空和前飛，希望能在不同的飛行狀態下獲得最佳的弦長設計值。因爲弦長是計算輸出功率或推力的主要因素，所以弦長將是主要的設計參數；當求得最佳的設計參數時，則最佳的外形設計也就得到了。相信本研究之結果能對直昇機旋翼葉片的設計提供重要的依據。 This study presents an application of optimality criteria method for a helicopter rotor blade design through au unsteady aerodynamic consideration. The method used in blade optimization is the concept of Khun-Tucker necessary condition, which to minimize the power output and also maintain the lift force with the optimum configuration of the blade. The unsteady aerodynamic environment used for the blade design contains the coupling of wake dynamics and aerodynamics. The Peters' finite state inflow theory is chosen for a wake modeling. The blade element theory and lifting line theory are used to formulate the aerodynamic force (lift) for a blade. Two flight conditions (hover and forward flight) will be considered in this study. The chord length will be implemented as design variables to calculate the lift or thrust. The best configuration design of the rotor blade can be obtained when the design variables are solved. The numerical results and analysis provide the important information of helicopter rotor blade design.
關聯:
中國航空太空學會學刊=Transactions of the Aeronautical and Astronautical Society of the Republic of China 28(3)，頁193-201
