非对称气动布局弹箭的耦合运动机理及运动稳定性研究

Projectiles with asymmetric aerodynamic configuration can generate complex scanning motion mode, and they have wide application prospect in the field of aerospace exploration and smart munitions. But their nonlinear coupled motion mechanism and dynamic stability haven't been deeply studied.Taking projectiles with asymmetric aerodynamic configuration as research object, the key problems of their nonlinear coupled dynamics and dynamic stability are studied. By wind tunnel tests, the characteristics of flow field, the generation and fall-off process of the unsteady whirlpool are analyzed. Considering the asymmetric of mass distribution and aerodynamic configuration, nonlinear of aerodynamic forces and moments, and the rigid-flexible coupled effects of projectile and wings, the nonlinear multibody dynamic model is established. Scanning motion mechanism of the projectiles with asymmetric aerodynamic configuration is revealed. Then, nonlinear disturbance model is set up, the criterion of dynamic stability is derived, and parametric dynamic stability regions are obtained. The rules how the aerodynamic configuration parameters and structure parameters affect stability domain is revealed. By free flight tests, the quantitative relationship among structure configuration, aerodynamic characteristics, motion law and dynamic stability is studied, and the structure parameters of projectiles with asymmetric aerodynamic configuration are optimized. The results are helpful to roundly reveal motion mechanism of projectiles with asymmetric aerodynamic configuration and control their dynamic stability. Also, the results can provide some helpful references for the overall design of similar aircrafts.

非对称气动布局弹箭能够形成复杂的扫描运动，在空间探测和新型智能弹药领域有广泛的应用前景，但其非线性耦合运动机理及稳定性研究尚未深入。本项目以非对称双翼气动布局弹箭为对象，围绕其非线性耦合动力学和运动稳定性问题展开研究。通过风洞实验研究弹箭流场变化和非定常涡的产生、脱落过程。充分考虑系统质量分布和气动布局的非对称性、力和力矩的非线性以及弹-翼刚柔耦合等因素，建立非对称气动布局弹箭的非线性多体系统动力学模型，阐明非对称布局弹箭的扫描运动机理。建立非线性运动的扰动模型，推导非对称气动布局弹箭运动稳定性判据，给出参数化形式的运动稳定区间，揭示气动布局参数及弹体参数对其稳定域的影响规律。通过自由飞行试实验，研究结构布局与气动特性、运动规律和稳定性之间的定量关系，优化非对称气动布局弹箭的最优结构参数。本课题研究成果有助于全面揭示非对称气动布局弹箭运动机理和对其进行稳定性控制，指导同类飞行器总体设计。

采用理论建模、数值模拟和试验研究相结合的方法，以非对称双翼气动布局弹箭为对象，围绕其尾翼气动弹性、非线性耦合动力学和运动稳定性问题进行了系统的研究，研究成果可为该类弹箭的结构优化设计和推广应用提供了理论依据和技术支持。.（1）基于双向流固耦合方法，建立了非对称气动布局弹箭尾翼气动弹性问题的数值仿真方法，对带有刚性尾翼和柔性尾翼非对称气动布局弹箭进行了建模仿真，得到了不同边界条件下，尾翼挠曲变形情况，以及挠曲变形对弹箭气动特性的影响规律，得到了尾翼结构参数，对无弹箭气动特性的影响。.（2）在前期研究工作基础上，提出了基于功的互等定理的翼片挠曲变形的理论计算方法。对三种尾翼结构（平板翼片、S型翼片和C型翼片）在均布气动力载荷作用下的挠曲变形进行了求解，得到了三种尾翼结构挠曲度随来流速度的变化规律，理论计算结果与仿真计算结果吻合良好。.（3）结合气动特性研究结果，建立了非对称气动布局弹箭的多刚体动力学方程，通过坐标变换求解了扫描线方程，根据奇点理论，得到了运动稳定性判据，获得了明确以参数化方式表示的运动稳定区间，阐明各结构参量对非对称气动布局弹箭运动稳定性的影响规律。为其稳态扫描设计及参数提供了重要的理论支持。.（4）针对不同的优化目标，采用正交实验方法和多目标遗传算法对两片翼和四片翼的非对称气动布局弹箭进行了气动外形优化设计。基于正交试验方法，得到了S-S型及S-C型无伞末敏弹优化模型，并通过高塔自由飞行试验验证了优化效果。采用基于多目标遗传算法的优化方法，对四片翼非对称气动布局弹箭，弹箭开展了以增旋、减阻为目标的气动外形多目标优化设计，获得了兼顾减小阻力系数和提高平衡转速的尾翼结构优化方案。.除此之外，继续深入分析课题中的学术亮点及制约本项技术发展的关键技术，进一步开展了带有扭曲尾翼结构的新型掠飞末敏弹气动特性、飞行稳定性、稳态扫描特性以及命中概率等研究。