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以某型手抛式太阳能无人机(UAV)模型为对象进行考虑多螺旋桨滑流影响的低雷诺数机翼平面形状设计研究。首先,基于升力面理论发展了准定常求解多螺旋桨/机翼相互气动干扰问题的涡格法(VLM)程序,并采用建立参考翼型气动特性数据库的形式发展了相关低雷诺数修正(LRC)方法;然后,通过对翼型、低雷诺数机翼及单螺旋桨/机翼算例的数值模拟及与相关实验结果的对比,验证了本文数值方法具备模拟低雷诺数复杂流动问题的可靠性及准确性;最后,对某型手抛式太阳能无人机简化拉力多螺旋桨/机翼模型进行了直接优化设计及反设计,并通过具有较高精度的CFD准定常求解技术对优化结果进行了验证。结果表明:以CFD方法计算结果为参考,本文涡格法程序及低雷诺数修正方法能够准确高效地计算相关低雷诺数复杂流动问题;传统未考虑多螺旋桨滑流影响的设计机翼在实际螺旋桨工作状态下将偏离设计点,机翼气动特性得不到提高;考虑螺旋桨滑流影响的优化设计方法能够有效改善机翼阻力特性,相对应地,在设计状态下优化机翼总阻力能够降低19.52counts。
The planar shape design of low Reynolds number wing considering the effect of multi-propeller slipstream is studied for a type of hand-throw solar unmanned aerial vehicle (UAV) model. Firstly, based on the theory of lift surface, a vortex lattice (VLM) program for quasi-steady solution to the mutual aerodynamic interference of multiple propellers / airfoils has been developed and correlated low Reynolds number correction (LRC) has been developed by establishing a reference airfoil aerodynamic characteristic database. Then, the numerical simulation of the airfoil, the low Reynolds number wing and the single propeller / wing and the comparison with the experimental results show that the numerical method possesses the reliability of simulating low Reynolds number complex flow and Accuracy. Finally, direct optimization design and inverse design of a simplified model of hand-held solar drone simplified RPLM are carried out, and the optimization results are verified by CFD quasi-constant solution with high accuracy . The results show that the proposed method can accurately and efficiently calculate the complex low-Reynolds number flow problems by using the CFD method and the low Reynolds number correction method. The traditional design of the wing, which does not consider the effects of multiple-propeller slipstream, The aerodynamic characteristics of the wing can not be improved under the working condition; the optimized design method considering the effects of the propeller slip can effectively improve the wing resistance characteristics. Correspondingly, the optimization of the total wing resistance can be reduced by 19.52 counts.