航空发动机转子系统动力学模型的可逆化简化方法

针对航空发动机高压转子系统动力学模型,给出了一种模型可逆化简化的方法.首先采用有限元法建立了较为精确的动力学模型,然后基于质心集中方法对该模型进行了不同程度的简化,分别得到了单跨双盘模型和单盘模型,并将其与原始模型进行了临界转速的对比.这是一种从结构特点将实际多盘转子简化成单盘转子的方法,它使得在考虑到支承等非线性因素后利用低维非线性动力学理论进行分析和参数优化成为可能.另一方面,研究了模型简化方法的可逆性,即基于质心位置及总质量最优的原则,由单跨双盘模型的圆盘结构参数反推了多级圆盘的等效内外半径、厚度、位置等参数,构建了新的工程结构模型,对比该模型和原始模型的前3阶临界转速,误差均在3%之内.这种由简化模型参数反推多级圆盘的方法,为由非线性动力学理论优化分析所得到的简化模型优化结构参数反推设计多级圆盘工程结构参数奠定了基础. 

Reversible model-simplifying method for aero-engine rotor systems

A reversible simplified method was given to investigate the dynamic model for aero-engine high-pressure rotor system. By using the finite element method, the accurate complex dynamics model was built, and also simplified to gain the single-span with dual-disc model and single-disc model based on the center of mass concentration method. The critical whirling speed was compared for the simplified and complex models to indicate the correctness of the simplified method. This modeling-simplify method based on the structural characteristics made low-dimensional nonlinear dynamics analysis and parameter optimization possible with the consideration of the nonlinear factors of supporting, etc. And then the reversibility of the model-simplifying method was investigated. The new complex model and the discs' parameters of equivalent radius, thickness and location were obtained from the single-span with dual-disc model by the principle of optimized centroid location and the total mass of the discs. The 1th to 3th critical whirling speeds of the new complex model and the original model were compared, indicating that the errors were all less than 3%. The reversible model-simplifying method laid the foundation for the multistage-disc's engineering structural parameters design from the simple model structural parameters optimized by the nonlinear dynamics theory.