考虑流固耦合效应的航空发动机风扇叶片应力数值模拟与试验测量研究

Numerical Simulation and Experimental Measurement of Aero-Engine Fan Blade Stress Considering Influence of Fluid-Structure Interaction

关键词:  航空发动机  风扇转子  叶片应力  数值模拟  流固耦合  试验测量

Key words:  Aero-engine  Fan rotor  Blade stress  Numerical simulation  Fluid-Structure interaction  Experimental measurement

摘要:

航空发动机风扇转子在高压比、高转速、高负荷的级环境中工作时，存在叶片固体域与流体域之间强烈的耦合作用。针对风扇工作中的流固耦合问题，采用基于流固耦合的数值模拟方法对风扇叶片的结构特性进行模拟，研究考虑流固耦合效应前后叶片结构特性的变化。通过风扇转子加减速试验测量叶片表面测点应力变化，并将数值模拟与试验测量结果进行了对比分析。分析结果表明：考虑流固耦合效应后叶片表面的受力情况变化较大，导致叶片表面的应力与变形分布产生较大的变化；仅考虑离心力作用的计算方法得到的应力值与试验测量值误差最大达到50%，而考虑流固耦合效应的计算值误差在10%左右；考虑叶片流固耦合效应得到的应力分布更满足实际工程应力与强度分析要求。

Abstract:

When the fan rotor of aero-engine works in the stage of high pressure ratio， high speed and high load， there is a strong coupling between the blade solid domain and the fluid domain. In order to solve the problem of fluid-structure interaction in the work of fan， the numerical simulation method based on fluid-structure interaction was used to simulate the structural characteristics of fan blades. In addition， the changes of blade structural characteristics before and after considering the effect of fluid-structure interaction were studied. Through the acceleration and deceleration test of the fan rotor， the stress changes of the measuring points on the blade surface were measured， and the numerical simulation was compared with the test results. The results show that the stress distribution on the blade surface changes greatly after considering the fluid-solid interaction effect， which leads to the great change of the stress and deformation distribution on the blade surface. The maximum error between the stress value obtained by the calculation method only considering the centrifugal force effect and the measured value is 50%， while the error of the calculated value considering the fluid-solid interaction effect is about 10%. Accordingly， the stress distribution obtained by considering the fluid-structure interaction effect of blade can meet the requirements of actual engineering stress and strength analysis.