【作者】 刘滔； 马宝峰；

【Author】 Liu Tao;Ma Baofeng;Ministry-of-Education Key Laboratory of Fluid Mechanics, Beihang University;

【机构】 北京航空航天大学流体力学教育部重点实验室；

【摘要】 针对常规布局无人机开展了基于伴随算子的气动外形优化设计研究。采用自由变形(FFD)技术参数化机翼和机身,以实现优化过程中机翼和机身的变形。FFD控制点为设计变量,采用离散伴随优化方法求解目标函数对设计变量的梯度,避免了由多设计变量引起的梯度求解计算量大的问题,提高了优化计算效率。优化过程中固定升力,施加待优化部位的几何约束、FFD控制点的位移约束,研究了有/无机翼扭转角作为设计变量时机翼的气动外形优化设计,以及研究了机身和机翼同时作为优化对象时的全机气动外形优化设计。优化结果表明,仅机翼作为设计对象时,优化后机翼表面压力分布均得到明显改善,整体阻力减小,俯仰力矩减小,无机翼扭转设计变量得到的俯仰力矩较有机翼扭转设计变量得到俯仰力矩更小;当机翼和机身同时作为优化对象时,俯仰力矩略微增大,无人机整体阻力降低,表明机身优化可以改善俯仰力矩的恶化,优化结果具有工程实用性。更多还原

【Abstract】 Research on adjoint operators based aerodynamic shape optimization design of UAV with conventional configuration is presented. Free deformation(FFD) technology is used to parameterize the wing and fuselage to morph the wing and fuselage during the optimization process. The vertex of the FFD control body is the design variable. discrete adjoint equation is used for solving the gradient of the objective function with respect to the design variables, which avoids computation cost amount of gradient solution caused by multiple design variables. Improved the optimization calculation efficiency. During the optimization process,the lift is fixed, the geometry of design object and the displacement of the FFD control vertex is constrained.The aerodynamic shape optimization design of the wing with and without the twist design variable has been researched. The case where both the fuselage and the wings are optimized at the same time has also been studied. The results of optimization show that when only the wing is used as the design object, the pressure distribution of the optimized wing is significantly improved, the overall drag is reduced, and the pitching moment is reduced. The optimized pitching moment without wing twist design variables is smaller than that with wing twist design variables. When the wing and the fuselage are optimized at the same time, the pitching moment increases slightly, and the overall drag of the UAV is decreased, indicating that the optimization with fuselage can improve the deterioration of the pitching moment. The optimization results have a certain engineering practicability.更多还原