Title: A Numerical Investigation of the Aeroelastic Interaction between Transonic Buffet and Structural Nonlinearity Show Chinese title

Title: 跨音速颤振与结构非线性的气弹相互作用的数值研究

Abstract: Transonic shock buffet is a nonlinear, unsteady aerodynamic phenomenon characterized by self-sustained, periodic shock oscillations that can critically affect aircraft structural integrity. While the aerodynamic aspects of shock buffet have been widely studied, its interaction with nonlinear structural dynamics remains largely unexplored. This paper presents, for the first time, a numerical investigation of aeroelastic interactions arising from the coupling of shock buffet with a nonlinear structural model featuring pitch freeplay. Using unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations coupled with a two-degree-of-freedom heave-pitch airfoil model, the study reveals that structural nonlinearity can induce aerodynamic lock-in to superharmonics of the heave natural frequency, resulting in 2:1 and 3:1 resonance mechanisms and large-amplitude heave limit cycles. These newly identified resonance behaviors expand the current understanding of transonic aeroelastic instabilities. The influence of key parameters such as structural-to-fluid mass ratio and structural damping on these phenomena is also systematically examined. This work introduces a novel class of aeroelastic lock-in mechanisms with significant implications for transonic flight dynamics and aircraft design. Show Chinese abstract

Abstract: 跨音速激波抖振是一种非线性、非定常的空气动力学现象，特征是自维持的周期性激波振荡，这种振荡可能严重影响飞机结构的完整性。尽管激波抖振的空气动力学方面已经被广泛研究，但其与非线性结构动力学的相互作用仍很大程度上未被探索。 本文首次通过数值方法研究了由于激波抖振与具有俯仰自由度间隙的非线性结构模型耦合而产生的气弹交互作用。利用非定常雷诺平均纳维-斯托克斯（URANS）模拟与两自由度的垂直-俯仰翼型模型相结合的研究表明，结构非线性可以诱导气动锁定到垂向固有频率的倍频上，从而导致2:1和3:1的共振机制以及大振幅的垂向极限环。这些新发现的共振行为扩展了对跨音速气弹不稳定性的当前理解。 此外，该研究还系统地考察了诸如结构与流体质量比和结构阻尼等关键参数对这些现象的影响。这项工作引入了一类新的气弹锁定机制，这对跨音速飞行动力学和飞机设计具有重要意义。