Prediction of the thermal bow of rotor based on the measured displacement and temperature

He Peng,Zhaohua Zhou,Jigang Feng,Xiangyu Yu,Zhansheng Liu

doi:10.1177/1550147720962993

He Peng, Zhaohua Zhou + Show 3 more

Open Access

https://doi.org/10.1177/1550147720962993

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Abstract

The thermal bow of the rotor occurs in the cooling process after the shutdown of the aeroengine. The deflection of the bowed rotor is the primary concern of the research on this problem. The objective of this work is to propose a method to predict the bow shape of the rotor with the measured temperature and displacement in a rotor thermal bow experiment. The experiment was introduced and the variations of the measured temperature and displacement were analyzed. A series of polynomial function was proposed to model the bowed shape of the rotor. The measured temperature and displacement were taken into considered in the constraint equations, with which the coefficients in the polynomial function were obtained. The bow shapes of the rotor at different time in the experiments were analyzed. Results showed that the maximum deflection of the rotor was much greater than the measured displacement at the sections near the rotor support. The forced cooling could reduce the thermal deflection of the rotor quickly. The analysis of the different cases of experiment indicated that the proposed method could predict the bow shape of the rotor with the measured temperature and displacement.

Highlights

The natural convection in the cooling process of the aeroengine generates a vertical temperature gradient on the rotor, which leads to the thermal bow of the rotor
As it is difficult to measure the displacement in high temperature environment, only few displacement measurements and a number of temperature measurements are generally recorded in the experimental research works
The transient bow shape of the rotor at different time of the experiment could be obtained by the obtained polynomial function

Summary

Introduction

The natural convection in the cooling process of the aeroengine generates a vertical temperature gradient on the rotor, which leads to the thermal bow of the rotor. The eccentricity results from the thermal bow generally causes high vibration of the rotor,[1,2] even rub between the rotor and the stator during the restart of the aeroengine.[3] The shape of the bowed rotor, with which the dynamics of the rotor could be analyzed,[1,4] is the primary concern in the research on the thermal bow problem. As it is difficult to measure the displacement in high temperature environment, only few displacement measurements and a number of temperature measurements are generally recorded in the experimental research works. The detailed shape of the thermal bow has not been predicted by any experiment yet. The objective of this work is to propose a method to predict the detailed

Objectives

Results

Conclusion