Session: 37-04 Unsteady Flow Modeling

Paper Number: 83460

83460 - Harmonic Method for Simulating Unsteady Multispool Interactions 

Modern jet engines normally arrange components on spools with different rotational speeds in order to improve compressor stall margin and overall engine performance. The unsteady interactions among these components can be significant and should be considered at an early design stage if possible.  A time-consuming time-marching unsteady simulation is normally required to simulate these unsteady interactions. However, this is impractical at the design stage when large number of designs need to be assessed.  Harmonic methods are promising approaches to efficiently simulation unsteady interactions in turbomachinery simulations, but it is challenging to apply harmonic methods to multispool simulations and there is very limited literature on this topic. The aim of this work is to address this challenge.

 

This paper extends the Favre-averaged  non-linear harmonic method to simulate multispool turbomachinery components. A unified bladerow interface is detailed to transfer disturbances through bladerows with arbitrary blade counts at any rotational speed. The treatment of non-reflective boundary condition at near acoustic resonance is also highlighted for certain combination of blade counts. The capability of the proposed approach is demonstrated by simulating the unsteady interaction of fan blade and the front stage of intermediate compressors and also the transfer of hot streaks through high pressure and intermedia pressure turbines in a three-shaft engine.

 

Presenting Author: Feng Wang University of Oxford

Presenting Author Biography: Feng is a Senior Researcher in Turbomachinery CFD in Oxford University. He obtained his B.Eng. degree in thermal and power engineering from Xi’an Jiaotong University and his master and PhD degrees from the Department of Mechanical Engineering at Imperial College London.

Authors:

Feng Wang University of Oxford
Luca Di Mare University of Oxford