Su Weihua, Swei Sean Shan-Min, Zhu Guoming G
University of Alabama, Tuscaloosa, AL, 35487-0280.
NASA Ames Research Center, Moffett Field, CA, 94035.
J Aircr. 2016 Sep;53(5):1305-1316. doi: 10.2514/1.C033490. Epub 2016 Mar 10.
In this paper, optimum wing bending and torsion deformations are explored for a mission adaptive, highly flexible morphing aircraft. The complete highly flexible aircraft is modeled using a strain-based geometrically nonlinear beam formulation, coupled with unsteady aerodynamics and 6-dof rigid-body motions. Since there are no conventional discrete control surfaces for trimming the flexible aircraft, the design space for searching the optimum wing geometries is enlarged. To achieve high performance flight, the wing geometry is best tailored according to the specific flight mission needs. In this study, the steady level flight and the coordinated turn flight are considered, and the optimum wing deformations with the minimum drag at these flight conditions are searched by utilizing a modal-based optimization procedure, subject to the trim and other constraints. The numerical study verifies the feasibility of the modal-based optimization approach, and shows the resulting optimum wing configuration and its sensitivity under different flight profiles.
本文针对任务自适应、高度灵活的变形飞机，探讨了最佳机翼弯曲和扭转变形。采用基于应变的几何非线性梁公式对完整的高度灵活飞机进行建模，并结合非定常空气动力学和六自由度刚体运动。由于没有用于调整柔性飞机的传统离散控制面，因此扩大了搜索最佳机翼几何形状的设计空间。为实现高性能飞行，机翼几何形状最好根据特定飞行任务需求进行定制。在本研究中，考虑了稳态平飞和协调转弯飞行，并利用基于模态的优化程序在这些飞行条件下搜索具有最小阻力的最佳机翼变形，同时考虑配平和其他约束条件。数值研究验证了基于模态的优化方法的可行性，并展示了不同飞行剖面下得到的最佳机翼构型及其敏感性。
