Study on the Mechanism of a Carrier-based Engine Parts' Performance Decline and Its Impact on the Whole Engine Performance

Wu Heng,Li Benwei,Wang Yonghua,Zhao Shufan,Dan Zhang

doi:10.1051/matecconf/201817901012

Abstract

The technical approach "use – parts' change - engine performance change" has been adopted to study and analyse the gas unit parts' performance changes of an engine after a long time operation. The mechanism of performance decline of the turbine is analysed based on the numerical simulation, the impact of components' performance decline on overall engine performance is studied and the correlation analysis is carried out. The results show that the change of turbine tip clearance, roughness increase and surface change will lead to the enhancement of secondary flow and the increase of influence area, and the turbulence effect is strengthened, resulting in the decrease of turbine circulation capacity and efficiency. The booster ratio of high pressure compressor, the flow capacity of high pressure and low pressure turbines, the flow capacity and efficiency of fan are the major component parameters causing the overall engine performance's degradation. And it also provides theoretical basis for the prevention of engine performance's degradation and online washing of parts and the whole machine.

Highlights

The engine of a navy carrier aircraft should meet the requirements of the escape away for slipping off
The oil on the high-pressure turbine wheel increases the possibility of further fouling, profile change, and roughness increase in the follow-up process
After a long period of operation, the engine performance changes mainly reflects in thrust drop and fuel consumption increases, the acceleration performance of the engine decreases slightly, but not obvious

Summary

Introduction

The engine of a navy carrier aircraft should meet the requirements of the escape away for slipping off. The decrease of thrust and other indicators will directly affect the flight safety of the carrier aircraft. Component performance change process has been analysed by means of experimental and numerical analysis at home[8,9,10,11,12]. The technical approach "use – parts’ change - engine performance change" has been adopted to study and analyse the gas unit parts’ performance changes of an engine after running 100h. Based on the numerical simulation, the performance degradation mechanism of the fan and turbine are analysed, the influence of component performance degradation on the whole machine performance is studied and the correlation analysis is carried out, and the characteristic parameters of the gas unit parts are extracted. It is found that after a long period operation, there is no significant change in the appearance of the air intake casing, but the oxide layer of adjustable leaves’ micro-arc is peeled off, and there are local drum phenomenon, as is shown in Figure 1, the peeling off of the adjustable blade protective layer and local drum phenomenon directly affect the smoothness of the airflow channel, while the leaves’ material is aluminium alloy so that salt spray corrosion is relatively poor, in ship-borne conditions the adjustable blade protection layer peeling off will cause further corrosion, change the fan flow conditions, affecting the overall performance of the fan

Conclusion

Reconstruction and correction of geometric model

Simulation results analysis

Analysis on the law of change of whole machine performance

Findings

Equations and mathematics Conclusion