流-固-推进耦合下的机体/推进一体化性能分析

Airframe-Propulsion Integrated Performance under Fluid-Structure-Propulsion Coupling

关键词:  吸气式  高马赫数  机体/推进一体化  本征正交分解  流-固-推进耦合

Key words:  Air-breathing  High Mach number  Airframe-propulsion integration  Proper orthogonal decomposition  Fluid-structure-propulsion coupling

摘要:

吸气式空天飞行器的一体化性能随扰动变化的敏感性高，在高马赫数飞行条件下，有必要开展流-固-推进耦合性能分析。针对机体/推进一体化布局的吸气式飞行器，明确一体化部件之间的耦合关系和耦合问题，利用CFD、有限元和准一维流方法，结合本征正交分解（Proper Orthogonal Decomposition,POD）降阶手段，建立吸气式空天飞行器流-固-推进多物理场耦合快速分析方法，并开展多场耦合特性分析。结果表明：（1）进气道压缩面的流-固耦合导致出口静压的最大振荡振幅约为平均静压的21.6%，而出口马赫数的最大振幅约为平均马赫数的8.45%。（2）进气道出口性能的振荡会影响发动机的推力性能，导致推力振荡幅值可达平均值的31%，且随着时间的推移，会在进气道外压缩流场产生大量的气动涡，涡结构进入进气道后会导致进气道出口性能的持续下降，进一步削弱了发动机的平均推力性能。

Abstract:

The integrated performance is sensitive to the disturbance for the air-breathing vehicle. In high Mach number condition, the research on the fluid-structure-propulsion coupling analysis is very important. The air-breathing vehicle is studied in this paper. The coupling relationship and problem are cleared. The method of fluid-structure-propulsion coupling analysis for aerospace is established based on CFD, finite element method and quasi one dimensional method. The rapidly analyzed method of multi-physical coupling is introduced by Proper Orthogonal Decomposition (POD) method. The coupling performance is studied. The results show that: （1) The exit maximum pressure oscillation amplitude is 21.6% of the average pressure under the influence of fluid-structure interaction on inlet compression surface, and the maximum Mach number oscillation amplitude is 8.45% of the average Mach number. （2) The vibration of the inlet exit performance will influence the thrust performance of the engine. The vibration amplitude of the thrust can reach up to 31% of the average performance. As the time goes on, a large amount of aerodynamic eddies are produced in the external compressed flow field of the inlet. When eddies enter into the inlet, the inlet exit average performance decreases, which further reduces the thrust of the engine.