The structural geometric nonlinearity has a great influence on the transonic aeroelastic characteristics of aircraft wings, which is an important problem for the aerodynamic and structural design of wing. In this paper, a CFD/CSD coupling method based on the high precision in-house solver is first established, and the reliability of the CFD and the CFD/CSD coupling method is then verified. Subsequently, the effects of geometric nonlinearity on the transonic aeroelastic characteristics of wing under different dynamic pressures are studied. The results show that: (1) At low dynamic pressure conditions, for geometric linear wing structure, limit-cycle oscillation occurs at various angles of attack, and the limit-cycle oscillation amplitude decreases with the increases of angle of attack. At low angle of attack, the wing deformation characteristics are dominated by first bending and first torsion, and the first torsion weaken as the angle of attack increases. For the geometric nonlinear wing structure, the limit-cycle oscillation occurs only at an attack angle of 0° As the angle of attack increases, the structural displacement eventually exhibits static deformation characteristics. (2) Under high dynamic pressure conditions: the displacement of geometric linear wing structure presents a divergent trend. For geometric nonlinear wing structure, the limit-cycle oscillation amplitude decreases first and then increases with the increase of the angle of attack. At low angle of attack, the deformation characteristics of the wing are dominated by first bending and first torsion. With the increase of the angle of attack, the first torsion weakens, while the second bending strengthen. With the further increase of the angle of attack, the second bending weaken and become co-dominated by the first bending and first torsion. It can be seen from the above results that the aeroelastic characteristics of both the geometric linear structure and the geometric nonlinear structure wings are significantly different. These findings provide valuable insights for the meticulous design of aircraft wings.

中文翻译：

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结构几何非线性对机翼跨音速气动弹性特性的影响


结构几何非线性对飞机机翼跨音速气动弹性特性影响较大，是机翼气动和结构设计的重要问题。本文首先建立了基于高精度内部求解器的CFD/CSD耦合方法，并验证了CFD和CFD/CSD耦合方法的可靠性。随后，研究了不同动压力下几何非线性对机翼跨音速气动弹性特性的影响。结果表明：（1）在低动压工况下，几何线性机翼结构在不同攻角下均会出现极限环振荡，且极限环振荡幅值随着攻角的增大而减小。小迎角时，机翼变形特征以初弯和初扭转为主，初扭随攻角增大而减弱。对于几何非线性机翼结构，仅在攻角为0°时才发生极限环振荡，随着攻角增大，结构位移最终表现出静态变形特征。 (2)高动压条件下：几何线性机翼结构的位移呈现发散趋势。对于几何非线性机翼结构，极限环振荡幅度随着攻角的增大先减小后增大。在低迎角时，机翼的变形特性以初弯和初扭转为主。随着攻角的增大，第一扭转减弱，第二弯曲增强。 随着攻角的进一步增大，第二弯曲减弱，并由第一弯曲和第一扭转共同主导。从上述结果可以看出，几何线性结构机翼和几何非线性结构机翼的气动弹性特性存在显着差异。这些发现为飞机机翼的精心设计提供了宝贵的见解。