Numerical Simulation Of Axial Compressor With Inlet Distortion And Rotating Stall

Aircraft engine is one of the most important power devices of aeronautics vehicles.Research work in this field has been paid great attention since 1960 s.China has put a lot of efforts in aircraft engine research programs both for military and civilian use,for the purpose of improving the military strength and international standing of our country.Axial compressor is the core component of an aircraft engine.The working condition of the compressor has a great influence on the performance and stability of the whole engine system.This thesis investigates the performance of axial compressor with inlet distortion and rotating stall applying numerical method.A theoretical body force model is derived to study the flow in the compressor.The body force model divides the compressor into two parts: blade region and blade-free region.In blade-free region,the flow is governed by Reynolds-Averaging Navier-Stokes equations.In blade region,the flow is simplified by body force model.Rotor and stator blades are replaced by body force to interact with the internal flow in the compressor.The numerical simulation is performed on commercial software Ansys CFX.The feasibility of body force model is successfully validated on NASA Stage 37 compressor.Thus the body force model is fatherly applied to study the compressor performance with inlet distortion and rotating stall.Results illustrate that total temperature inlet distortion can cause a compression ability loss due to the high temperature fluid,while total pressure inlet distortion will lead to a significant redistribution of the flow which is more likely for the compressor to end up in a state of stall or surge.The stall process in NASA Stage 37 compressor is also simulated using body force model.In the case of small mass flow,disturbance develops along the circumferential direction and turns into a rotating stall eventually.Types of the stall inception and structures of the stall cells are also studied afterwards.As a physical simplified model of the compressor internal flow,body force model can reveal the main features of the flow field,which makes the model practicable in engineering design and engine tests.