采用流固耦合方法的整级叶片鸟撞击数值模拟

利用MSC.DYTRAN软件建立了鸟撞航空发动机叶片转子级瞬态动力学有限元模型,采用流固耦合算法,模拟受气动和离心载荷作用并稳定旋转的发动机转子叶片,遭受不同鸟体撞击的瞬态响应过程.计算结果表明:鸟体撞击会使叶片产生巨大的瞬时冲击应力;鸟体速度、密度和尺寸的增加,将迅速增加叶片的冲击应力峰值,当叶片硬化和变形能力达到充分发展后,冲击应力峰值的增加速度会变慢;同时,叶片材料静态硬化模量的增加也会提高冲击应力峰值,而静态屈服强度的增加则会减小冲击峰的作用时间.最后还进一步模拟了鸟撞使叶片发生失效破坏的过程.

Numerical simulation of bird impact on bladed rotor stage by fluid-solid coupling method

An aeroengine rotor stage finite element method(FEM) model with aerodynamic load and constant rotational speed was studied by using fluid-solid coupling method with MSC.DYTRAN software in this paper to investigate its transient dynamic response while suffering various bird impacts.Results show that great instantaneous impact stress exists in the blades during the swift impact.The peak stress will rapidly increase if the velocity,density and size of the bird increase;nevertheless this ascendant tendency can be blunted after the potential of material hardening and deformation abilities have sufficiently developed.The result also reveal that raising hardening modulus of the blade material can increase the impact stress as well,whereas raising material yield strength will reduce the action time of impact stress.Finally,a more complicated simulation,in which material failure was included,was carried out to investigate the process of blade failure caused by bird impact.