高速飞行器间隙非线性机翼颤振的非线性能量阱抑制

针对间隙非线性机翼颤振系统的亚临界问题,引入了非线性能量阱(nonlinear energy sink,NES)技术来提高系统发生极限环振荡的临界速度。建立了具有NES控制的间隙非线性机翼颤振系统动力学模型,并分析了质量比、频率比、阻尼比、相对位置等NES参数对颤振系统极限环振荡的抑制效果,以及NES参数对颤振系统极限环振荡临界速度的影响规律。结果表明,阻尼比越大,可以在越小的自振频率比情况下使系统进入稳定区,但需要更苛刻的NES位置要求,即越靠近机翼前缘；而阻尼比越小,则使颤振系统极限环振荡响应进入稳定区所需的NES质量越小。在NES位置靠近机翼前缘时,增大自振频率比会使极限环振荡抑制效果有明显的提升,而增大质量比可以显著提高极限环振荡的抑制效果和临界速度。此外,NES的阻尼比越小,其颤振系统的极限环振荡抑制效果越好。

Suppression of nonlinear flutter for a wing with freeplay of high speed aircraft using nonlinear energy sink

The subcritical problem of wing flutter system with freeplay nonlinearity was addressed by introducing the NES(nonlinear energy sink) technology to improve the critical velocity of the system′s limit cycle oscillation. A dynamic model of flutter system with NES control for wings with freeplay nonlinearity was established, and the suppression effects of NES parameters such as mass ratio, frequency ratio, damping ratio, and relative position on the limit cycle oscillation of the flutter system were analyzed. The influence of NES parameters on the critical speed of the limit cycle oscillation of the flutter system was also investigated. The results show that a larger damping ratio can stabilize the system at a smaller natural frequency ratio but required a more stringent location requirement for the NES, i.e., closer to the leading edge of the wing. On the other hand, a smaller damping ratio results in a smaller NES mass required to stabilize the limit cycle response of the flutter system. When the NES location is closer to the leading edge of the wing, increasing the natural frequency ratio significantly improve the suppression effect of limit cycle oscillation, and increasing the mass ratio also significantly improve the suppression effect and critical speed of limit cycle oscillation. Additionally, a smaller damping ratio of the NES results in better suppression of limit cycle oscillation in the flutter system.