An Efficient Approach for Identification of the Inlet Distortion of Engine Based on Acoustic Emission Technique

Jiaoyan Huang,Aiguo Xia,Shenao Zou,Cong Han,Guoan Yang

doi:10.3390/app10228240

Abstract

Effective and accurate diagnosis of engine health is key to ensuring the safe operation of engines. Inlet distortion is due to the flow or the pressure variations. In the paper, an acoustic emission (AE) online monitoring technique, which has a faster response time compared with the ordinary vibration monitoring technique, is used to study the inlet distortion of an engine. The results show that with the deterioration of the inlet distortion, the characteristic parameters of AE signals clearly evolve in three stages. Stage I: when the inlet distortion J ≤ 30%, the characteristic parameters of the AE signal increase as J increases and the amplitude saturates at J = 23%, faster than the other three parameters (the strength, the root mean square (RMS), and the average signal level (ASL)). Stage II: when the inlet distortion 30% < J ≤ 43.64%, all the parameters saturate with only slight fluctuations as J increases and the engine works in an unstable statue. Stage III: when the inlet distortion J > 43.64%, the engine is prone to surge. Furthermore, an intelligent recognition method of the engine inlet distortion based on a unit parameter entropy and the back propagation (BP) neural network is constructed. The recognition accuracy is as high as 97.5%, and this method provides a new approach for engine health management.

Highlights

An engine typically encounters extreme environments which will result in the inlet distortion of the engine [1]
Analogous to the information entropy, this paper introduces a unit parameter entropy to evaluate the distribution of the acoustic emission (AE) parameters in a certain status of the engine
An engine was used to simulate disfunction inlet distortion, the AEof the monitoring technique was employed to identify thethe impact of inletofdistortion on theand stability monitoring technique was employed to identify the impact of inlet distortion on the stability of the engine

Summary

Introduction

An engine typically encounters extreme environments which will result in the inlet distortion of the engine [1]. The inlet distortion, which caused the high-cycle fatigue of turbomachinery components, is the main reason for the disfunction of the engine’s components. When a mild inlet distortion occurs, the vibration of the compressor becomes abnormal, reducing the efficiency of flight propulsion. Whereas when a severe inlet distortion occurs, there will be unrecoverable damage to the engine [2,3]. This can even surge the compressor, leading to a shutdown of the engine, affecting the safety of the engine. It is important to research the inlet distortion of the engine

Methods

Results

Conclusion