An 11-stage axial compressor performance simulation considering the change of tip clearance in different operating conditions

Abstract

The multistage axial compressor is one of the critical components of aero-engines and plays a key role in their performance, reliability, and economy. Tip clearance has a significant impact on the performance and stability of multistage axial compressors. Due to blade and disk deformations, tip clearance will vary significantly in different operating conditions. Thus, tip clearance should be accurately estimated when evaluating compressor performance. This paper proposes a new model to predict changes of tip clearance of multistage axial compressors in different operating conditions. A first-principles approach is used to estimate the change of tip clearance caused by thermal and mechanical deformation. The span-wise temperature distribution across each stage of the multistage compressors is considered by the proposed model in this paper. The model was validated by General Electric Company (GE) E3 engine experimental results. Using the model, the performance of an 11-stage axial compressor is simulated. The results show that accounting for tip clearance variations has a 0.5% impact on the calculated mass flow rate and a 1% impact on the calculated efficiency. Thus, variations of tip clearance at different operating conditions cannot be ignored and the proposed new model is useful to accurately predict the performance of multistage axial compressor.