Study on the Leakage and Inter-Stage Pressure Drop Characteristics of Two-Stage Finger Seal

Hailin Zhao,Hua Su,Yanchao Zhang,Guoding Chen

doi:10.3390/app11052239

Hailin Zhao, Hua Su + Show 2 more

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https://doi.org/10.3390/app11052239

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Abstract

To solve the high leakage and high wear problems faced by sealing devices in aeroengines under the condition of high axial pressure difference, the two-stage finger seal is proposed in this paper. The finite element method and computational fluid dynamics (FEM/CFD) coupling iterative algorithm of the two-stage finger seal is developed and validated. Then the performance advantages of two-stage finger seal compared to the one-stage finger seal are studied, as well as the leakage and the inter-stage pressure drop characteristics of two-stage finger seal are investigated. Finally, the measure to improve the inter-stage imbalance of pressure drop of two-stage finger seal is proposed. The results show that the two-stage finger seal has lower leakage and lower contact pressure than the one-stage finger seal at high axial pressure difference, but there exists an inter-stage imbalance of pressure drop. Increasing the axial pressure difference and the root mean square (RMS) roughness of finger element can aggravate the imbalance of pressure drop, while the radial displacement excitation of rotor has little influence on it. The results also indicate that the inter-stage imbalance of pressure drop of the two-stage finger seal can be improved by increasing the number of finger elements of the 1st finger seal and decreasing the number of finger elements of the 2nd finger seal.

Highlights

As an important component in an aeroengine, the sealing device has an important influence on its thrust-to-weight ratio and specific fuel consumption
Compared with redesigning and requalifying the compressor or turbine structural components to improve the performance of the aeroengine, the adoption of the advanced seal technology has the advantages of low investment and high benefit
The results show that the method built in this paper overestimates the leakage at high axial pressure difference, and this is mainly

Summary

Introduction

As an important component in an aeroengine, the sealing device has an important influence on its thrust-to-weight ratio and specific fuel consumption. Compared with redesigning and requalifying the compressor or turbine structural components to improve the performance of the aeroengine, the adoption of the advanced seal technology has the advantages of low investment and high benefit. Research has shown that the specific fuel consumption can be reduced by 2.5% by using advanced seals at only a few locations [2]. For these reasons, the sealing workers have conducted in-depth exploration and extensive research around the advanced sealing technology of aeroengines in recent years.

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