A novel method to improve the precision of BTT under rapid speed fluctuation conditions

A vibration monitoring system for rotating blade based on tip-timing is developed,and it consists of three parts,i.e. optical-fiber sensing,data acquisition and vibration analysis.The designs of tip-timing sensors and photoelectric converter are the important part of optical=fiber sensing.High-speed collection,preprocessing and communication with computer for transformed pulse data are realized in data acquisition part.In addition the real-time data processing and analytical result display are completed in vibration analysis part.The verification of the principle of the whole set system is completed on an on-site large compressor,while the real-time verification is passed on a high-speed stimulated rotor.The analysis results of asynchronous vibration are completely consistent with the data by strain gauge,thereby ensuring the successful application of the whole set of system in real-time on-line monitoring of the vibration of compressor blades.

Analysis of Non-contact Asynchronous Vibration of Rotating Blades Based on Tip-timing

Error revising of blade tip-timing parameter identification caused by frequency sweep rate

Error Revising of Blade Tip-Timing Parameter Identification Caused by Frequency Sweep Rate

The invention belongs to the field of non-contact distance measurement, and aims to realize non-contact real-time on-line accurate measurement of an axial clearance of a rotor and a stator of an aero-engine under a space limited condition. Therefore, the technical scheme adopted by the invention is as follows: the microwave-based rotor and stator axial clearance online measurement device is composed of a microwave signal generation module, a signal power amplification module, a signal receiving and mixing module, a signal conditioning and acquisition module, a circulator and a microwave sensor, and a carrier signal generated by the microwave signal generation module enters a first port of the circulator after being amplified by the signal power amplification module and is output from a second port of the circulator; and the second port of the circulator is connected with the microwave sensor, and the microwave sensor transmits a carrier signal to the axial end surface of the measured rotor, receives a carrier reflection signal of the axial end surface of the rotor, outputs the carrier reflection signal to the second port of the circulator and outputs the carrier reflection signal from the third port of the circulator. The invention is mainly applied to non-contact distance measurement occasions.

Microwave-based rotor and stator axial clearance online measurement method and device

Tip-timing technology has been widely used to monitor blade vibration of the aeroengine. In the off-line analysis of tip-timing signals, it is key and a prerequisite in blade fault diagnosis to locate the vibration event accurately. It is the most common method used to locate abnormal vibration based on the correlation of tip-timing data in adjacent revolutions. However, the data in the adjacent revolutions only include little vibration information, which results in the location performance being susceptible to noise. This paper located the vibration event using the area of the ellipse calculated based on the two-parameter plot. The relationship between the area of the fitted ellipse and the blade vibration parameters was derived for the first time in this paper. The feasibility of the method was verified using the tip-timing data of the low-pressure fan of an aeroengine. The results showed that the method can locate both synchronous resonance and rotating stall accurately. Its performance in anti-noise interference was far superior to the correlation coefficient methods due to enough information provided by multi-revolutions rather than only two revolutions. The work in this paper is of great significance for the realization of automatic processing of tip-timing signals.

The location method of blade vibration events based on the tip-timing signal

Identification of the excitation source's circumferential position for rotating blades based on vibration phase

The utility model belongs to the field of non-contact distance measurement. The objective of the utility model is to realize non-contact real-time on-line accurate measurement of the axial clearance of the rotor and the stator of the aero-engine under a space limited condition. The utility model provides a technical scheme. The utility model discloses a microwave-based rotor and stator axial clearance online measurement device. The device is composed of a microwave signal generation module, a signal power amplification module, a signal receiving and mixing module, a signal conditioning and acquisition module, a circulator and a microwave sensor, and a carrier signal generated by the microwave signal generation module enters a first port of the circulator after being amplified by the signalpower amplification module and is output from a second port of the circulator; and the second port of the circulator is connected with the microwave sensor, and the microwave sensor transmits a carrier signal to the axial end surface of the measured rotor, receives a carrier reflection signal of the axial end surface of the rotor, outputs the carrier reflection signal to the second port of the circulator and outputs the carrier reflection signal from the third port of the circulator. The non-contact distance measuring device is mainly applied to non-contact distance measuring occasions.

Fengyao Zhi

Papers

The location method of blade vibration events based on the tip-timing signal

Identification of the excitation source's circumferential position for rotating blades based on vibration phase

Rotor and stator axial clearance online measuring device based on microwaves

Microwave-based rotor and stator axial clearance online measurement method and device