Study on a Fault Mitigation Scheme for Rub-Impact of an Aero-Engine Based on NiTi Wires.

Qiang Pan,Xiaofeng Liu,Tian He,Haibing Chen,Wendong Liu

doi:10.3390/s22051796

Abstract

The aim of this study was to solve the frequently occurring rotor-stator rub-impact fault in aero-engines without causing a significant reduction in efficiency. We proposed a fault mitigation scheme, using shape memory alloy (SMA) wire, whereby the tip clearance between the rotor and the stator is adjusted. In this scheme, an acoustic emission (AE) sensor is utilized to monitor the rub-impact fault. An active control actuator is designed with pre-strained two-way SMA wires, driven by an electric current via an Arduino control board, to mitigate the rub-impact fault once it occurs. In order to investigate the feasibility of the proposed scheme, a series of tests on the material properties of NiTi wires, including heating response rate, ultimate strain, free recovery rate, and restoring force, were carried out. A prototype of the actuator was designed, manufactured, and tested under various conditions. The experimental result verifies that the proposed scheme has the potential to mitigate or eliminate the rotor-stator rub-impact fault in aero-engines.

Highlights

The efficiency of a rotating machine such as an aero-engine is strongly dependent on the tip clearance between the stationary and rotating parts [1]
This paper presents a promising solution for rub-impact fault detection and mitigation for an aero-engine
This paper presents a promising solution for rub-impact fault detection and Typical shape memory alloy (SMA), such as NiTi, is capable of recovering its original shape after plastic demitigation for an aero-engine

Summary

Introduction

The efficiency of a rotating machine such as an aero-engine is strongly dependent on the tip clearance between the stationary and rotating parts [1]. Minimizing the clearance is usually associated with undesired rub-impact phenomena occurring between the rotor and the casing due to mechanical, aerodynamic excitation, or thermal gradience during engine operation [4,5]. This leads to material or structural damage, e.g., plastic deformations, changes in the microstructure on the blade tips, crack initiation, and the break out of liner material at the rubbing zone [6], and, sometimes, catastrophic accidents [7]. Most studies focused on how to monitor the occurrence of a fault and analyze its type or location; few were concerned with the mitigation or elimination of the rub-impact phenomenon

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