Urban forest parks are open parks based on natural countryside, which can be used for outdoor sports, leisure and recreation, popular science education and other activities. The trail is a pedestrian road connecting v...Urban forest parks are open parks based on natural countryside, which can be used for outdoor sports, leisure and recreation, popular science education and other activities. The trail is a pedestrian road connecting various landscape points in the park. It not only has directional and traffic functions, but also is the most effective means for the organization of the whole park. Taking Yaohu Country Forest Park in Nanchang City as an example, this study analyzed and discussed the design of trails and landscapes.展开更多
Wind tunnel testing and embedded large eddy simulations are employed to study the noise reduction of trailing-edge finlets on an airfoil. Trailing-edge finlets are shown to increase the distance between the highly ene...Wind tunnel testing and embedded large eddy simulations are employed to study the noise reduction of trailing-edge finlets on an airfoil. Trailing-edge finlets are shown to increase the distance between the highly energetic fluid particles and the sharp trailing edge. Experiments were conducted at different angles of attack. Wind tunnel measurements confirm that finlets reduce the broadband noise radiated by the airfoil. Results also reveal that the noise reduction of finlets is dependent on the airfoil angle of attack, and that the highest noise reduction is obtained at the largest angle of attack tested.展开更多
为了同时提高风力机大厚度翼型的气动性能和叶片的截面刚度,基于风力机翼型泛函集成理论和复合材料力学理论,提出了一种大厚度钝尾缘翼型优化设计方法,并建立了优化设计模型。该模型以翼型的气动性能最佳为设计目标,以叶片的最小截面刚...为了同时提高风力机大厚度翼型的气动性能和叶片的截面刚度,基于风力机翼型泛函集成理论和复合材料力学理论,提出了一种大厚度钝尾缘翼型优化设计方法,并建立了优化设计模型。该模型以翼型的气动性能最佳为设计目标,以叶片的最小截面刚度为约束条件,为某850 k W叶片(该叶片40%相对厚度处为DU00-W2-401翼型)优化设计了一种同厚度的新翼型—CQU-B-400。与DU00-W2-401相比,新翼型在光滑和粗糙条件下,气动性能均有较大提高;使用CQU-B-400翼型后,叶片的尾缘强度得到加强,叶片截面的挥舞刚度和摆振刚度也有一定的提高,表明新翼型能同时提高叶片的气动和结构性能。结果验证了所提出的大厚度翼型设计方法的可行性。展开更多
文摘Urban forest parks are open parks based on natural countryside, which can be used for outdoor sports, leisure and recreation, popular science education and other activities. The trail is a pedestrian road connecting various landscape points in the park. It not only has directional and traffic functions, but also is the most effective means for the organization of the whole park. Taking Yaohu Country Forest Park in Nanchang City as an example, this study analyzed and discussed the design of trails and landscapes.
文摘Wind tunnel testing and embedded large eddy simulations are employed to study the noise reduction of trailing-edge finlets on an airfoil. Trailing-edge finlets are shown to increase the distance between the highly energetic fluid particles and the sharp trailing edge. Experiments were conducted at different angles of attack. Wind tunnel measurements confirm that finlets reduce the broadband noise radiated by the airfoil. Results also reveal that the noise reduction of finlets is dependent on the airfoil angle of attack, and that the highest noise reduction is obtained at the largest angle of attack tested.
文摘为了同时提高风力机大厚度翼型的气动性能和叶片的截面刚度,基于风力机翼型泛函集成理论和复合材料力学理论,提出了一种大厚度钝尾缘翼型优化设计方法,并建立了优化设计模型。该模型以翼型的气动性能最佳为设计目标,以叶片的最小截面刚度为约束条件,为某850 k W叶片(该叶片40%相对厚度处为DU00-W2-401翼型)优化设计了一种同厚度的新翼型—CQU-B-400。与DU00-W2-401相比,新翼型在光滑和粗糙条件下,气动性能均有较大提高;使用CQU-B-400翼型后,叶片的尾缘强度得到加强,叶片截面的挥舞刚度和摆振刚度也有一定的提高,表明新翼型能同时提高叶片的气动和结构性能。结果验证了所提出的大厚度翼型设计方法的可行性。