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CN-121804870-B - Dynamic stress measuring device and method for unstable working state of engine

CN121804870BCN 121804870 BCN121804870 BCN 121804870BCN-121804870-B

Abstract

The application belongs to the technical field of engine measuring devices, and provides a dynamic stress measuring device and a dynamic stress measuring method for an unstable working state of an engine, wherein the measuring device comprises an experimental platform, the engine is fixedly arranged on the experimental platform, a helicopter air inlet of the engine is communicated with an air source through a pipeline, and an electromagnetic valve and an electric valve are sequentially arranged on the pipeline from the air source to the engine; the engine is connected with an air source from an air-entraining port of the helicopter, high-pressure air is injected into a combustion chamber through an air-entraining port of the helicopter, the pressure in front of a guide vane of the gas turbine is improved, the engine enters an unstable working state, and the strain of the impeller in the unstable working state is conveniently measured.

Inventors

  • LI XIN
  • YUE YANG
  • WEI HAILONG
  • LI LIXIN
  • Xiang Luyu
  • WANG XIHUA

Assignees

  • 中国航发湖南动力机械研究所

Dates

Publication Date
20260508
Application Date
20260312

Claims (8)

  1. 1. The dynamic stress measuring device for the unstable working state of the engine is characterized by comprising an experiment platform (20), wherein the experiment platform (20) is fixedly provided with the engine (40), a helicopter air outlet of the engine (40) is communicated with an air source (71) through a pipeline, an electromagnetic valve (73) and an electric valve (74) are sequentially arranged on the pipeline from the air source (71) to the engine (40), a gas compressor is arranged in the engine (40), a strain gauge (52) is arranged on an impeller (51) of the gas compressor, the strain gauge (52) is electrically connected with a dynamic stress measuring device (50), and the dynamic stress measuring device (50) is arranged on the experiment platform (20) and is positioned outside the engine (40); The method comprises the steps of installing a strain gauge (52) on an impeller (51) of an engine (40), and electrically connecting the strain gauge (52) with a dynamic stress measuring device (50); Starting the engine (40) to a ground slow-driving state, and staying for a period of time ; Pushing up the engine (40) to an idle slow state, dwell time period To complete the heat engine operation of the engine (40); acquiring a vibration scan rate at which the engine (40) is pushed up to a maximum operating state and held for a period of time Acquiring data of a full rotation speed range; acquiring a resonance rotation speed according to the data of the full rotation speed range, and controlling the engine (40) to enter the resonance rotation speed state and stay for a period of time Acquisition time period A pressure ratio of the engine (40); during a time period Wherein the gas in the gas source (71) enters the combustion chamber of the engine (40) and the gas pressure in the gas source (71) is greater than the turboshaft engine bleed port pressure, the engine (40) enters the unstable operating region for a period of time Comprising the following steps of during a time period The opening degree of the electric valve (74) is adjusted to enable the engine (40) to enter an unstable working area to deviate from a target state of normal working, and the time period is prolonged Recording the change condition of the pressure ratio of the air compressor; the dynamic stress measuring device (50) obtains a time period through the strain gauge (52) And (3) executing a stopping program of the engine (40) according to dynamic stress experimental data of the impeller (51).
  2. 2. An engine unsteady operating state dynamic stress measuring device as claimed in claim 1, characterized in that a pressure sensor (72) is also provided on the pipe, the pressure sensor (72) being located between the electromagnetic valve (73) and the air source (71).
  3. 3. The dynamic stress measuring device for the unstable operating state of the engine according to claim 1, wherein the dynamic stress measuring device (50) comprises a data acquisition system (55), and the data acquisition system (55) is electrically connected with the strain gauge (52).
  4. 4. The dynamic stress measuring device for the unstable operating state of the engine according to claim 3, wherein the dynamic stress measuring device (50) further comprises a lubrication and cooling system (54), a slip ring electric guide (53) is arranged on the engine (40), a wire of the strain gauge (52) is electrically connected with the data acquisition system (55) through the slip ring electric guide (53), and a lubrication pipeline of the lubrication and cooling system (54) is connected with a lubrication pipeline of the slip ring electric guide (53).
  5. 5. The apparatus for measuring dynamic stress in an unstable operating state of an engine according to claim 1, further comprising the step of, for a period of time And (3) processing the experimental number to obtain the change rule of the dynamic stress of different blade positions along with the pressure ratio under the unstable working state of the engine (40).
  6. 6. The apparatus of claim 1, wherein the vibration scanning rate is in the range of 50r/min/s to 200r/min/s.
  7. 7. An engine unstable operating condition dynamic stress measuring device according to claim 1, wherein the data of the full speed range includes the resonant frequency, amplitude, order and resonant speed of the impeller (51).
  8. 8. The dynamic stress measuring device for unstable operation of an engine according to claim 1, wherein the compressor pressure ratio is calculated as follows: pi=p2/p 1, where pi represents the compressor pressure ratio, p1 represents the compressor inlet pressure, and p2 represents the compressor outlet pressure.

Description

Dynamic stress measuring device and method for unstable working state of engine Technical Field The application belongs to the technical field of engine measuring devices, and particularly relates to a dynamic stress measuring device and method for an engine in an unstable working state. Background As the power of a helicopter, the aviation turboshaft engine needs to carry out a dynamic stress measurement test on the compressor blade in the development process, so as to verify whether the bearing load of the compressor blade meets the design strength requirement during operation. Various conditions and situations are encountered during actual use of a turboshaft engine, such as surge, which is a relatively common unstable operating condition. During surge, the airflow oscillates axially at low frequency in the compressor flow path, and the compressor blades are subjected to low frequency and high amplitude pressure shocks of the airflow, even reverse shocks, i.e. large transient shocks to the suction side (non-designed force bearing side) of the blades. Thus, the dynamic stress distribution of the unstable state compressor blade is obtained and is critical to its strength design. The prior art introduces a test method for measuring the dynamic stress of a compressor blade under the steady state of a turboshaft engine, and does not describe the test method for measuring the dynamic stress and the layout of test equipment when the turboshaft engine is in an unstable working state. There is a need for an apparatus and method for measuring dynamic stresses in compressor blades during unstable operating conditions of a turboshaft engine. Disclosure of Invention The application provides a dynamic stress measuring device for an unstable working state of an engine, which comprises an experiment platform, wherein the experiment platform is fixedly provided with the engine, an air inlet of a helicopter of the engine is communicated with an air source through a pipeline, an electromagnetic valve and an electric valve are sequentially arranged on the pipeline from the air source to the engine, a gas compressor is arranged in the engine, a strain gauge is arranged on an impeller of the gas compressor, the strain gauge is electrically connected with the dynamic stress measuring device, and the dynamic stress measuring device is arranged on the experiment platform and is positioned outside the engine. Further, a pressure sensor is also arranged on the pipeline, and the pressure sensor is positioned between the electromagnetic valve and the air source. Further, the dynamic stress measuring device comprises a data acquisition system, and the data acquisition system is electrically connected with the strain gauge. Further, the dynamic stress measuring device further comprises a lubrication cooling system, a slip ring electric guide is arranged on the engine, a wire of the strain gauge is electrically connected with the data acquisition system through the slip ring electric guide, and a lubrication pipeline of the lubrication cooling system is connected with a lubrication pipeline of the slip ring electric guide. The dynamic stress measuring method for the unstable working state of the engine adopts the device and comprises the following steps: The strain gauge is arranged on an impeller of the engine and is electrically connected with the dynamic stress measuring device; starting the engine to a ground slow-running state, and staying for a period of time ; Pushing up the engine to an empty slow state, and staying for a period of timeTo complete the heat engine work of the engine; Acquiring a vibration scanning rate, and pushing up the engine to a maximum running state at the vibration scanning rate and staying for a period of time Acquiring data of a full rotation speed range; acquiring a resonance rotating speed according to the data of the full rotating speed range, and controlling the engine to enter the resonance rotating speed state and stay for a period of time Acquisition time periodThe pressure ratio of the engine; during a time period Wherein the gas in the gas source enters the combustion chamber of the engine, the gas pressure in the gas source is larger than the pressure of the gas introducing port of the turboshaft engine, the engine enters an unstable working area and lasts for a period of time; Dynamic stress measuring device obtains time quantum through foil gageThe dynamic stress experimental data of the middle impeller are used for executing an engine stopping program; Further, the method also comprises the following steps of, for a time period And (3) processing the experimental number to obtain the change rule of the dynamic stress of different blade positions along with the pressure ratio under the unstable working state of the engine. Further, the vibration scanning rate ranges from 50r/min/s to 200r/min/s. Further, the data of the full rotation speed range includes the resonance frequency, amplitude, o