Algorithm And System Design Of Aeroengine Turbine Blade Radiation Temperature Measurement

Turbine blade temperature monitoring technology is a crucial technology for the development and operation monitoring of aero engine.It can not only ensure the safe operation of the engine,but also provide important data for the structural design and optimization of high performance engine turbine blades.However,the temperature measurement of the high-speed rotating turbine blade under high temperature and high pressure environment is always a technical problem.Radiation temperature measurement technology arises at the historic moment.It solves the defects of the contact temperature measurement technology,such as the interference of the measured surface temperature field distribution and the small number of measuring points.It has gradually been widely concerned and applied in the field of turbine blade temperature measurement.However,the technology of turbine blade radiation temperature measurement still has the problem of excessive measurement error caused by environmental radiation and emissivity changes.According to the current development status and application requirements of aeroengine turbine blade radiation temperature measurement technology.This paper studies the radiation temperature measurement Algorithm and optical system design,the main research work is divided into the following four parts:(1)The environmental radiation effect of turbine blade radiation temperature measurement was studied.The environmental radiation sources in the process of turbine blade radiation temperature measurement were analyzed.Aiming at the problem that the radiation effect of environmental blade is difficult to eliminate,a three-dimensional dynamic radiation transmission model based on radiation transmission theory and the real surface of engine turbine blade is proposed.The relationship between the radiation angle factor of environmental blade radiation and the rotation angle of target blade is analyzed,and the temperature measurement error of turbine blade at different temperatures and positions caused by reflected radiation is calculated.Under the set conditions,the maximum temperature measurement error is above 40 K.(2)Three-wavelength radiation temperature measurement of turbine blade based on reflection error correction is studied.Aiming at the influence of environmental radiation on temperature measurement and the difficulty of measuring blade emissivity,a three-wavelength radiation temperature measurement algorithm based on reflection error correction is proposed.The error function of three wavelength radiation temperature measurement algorithm is constructed.Combined with the measured actual radiation of the target surface,the simulation results of three-dimensional dynamic radiation transmission model and the environmental radiation calculated by reference to the actual radiation of the environmental blade,the surface temperature of the target blade is inversed.Then,the influence of measurement band,target temperature inversion Algorithm and emissivity difference on temperature measurement is analyzed,and the temperature measurement error caused by influencing factors is simulated and calculated.The validity and reliability of the algorithm are verified.(3)The design and integration of three-wavelength radiation temperature measurement optical system are studied.Aiming at the complex surface and high temperature working environment of aero-engine turbine blade,a three-wavelength radiation temperature measurement optical system for turbine blade radiation temperature measurement is designed.Firstly,the focusing scheme of the pre-focusing lens and the elimination Algorithm of the thermal effect are determined,the influence of the surface defocus amount on the receiving energy of the detector is analyzed.On this basis,the optical system of the three-wavelength radiation thermometry is designed,and the optical performance of the system at different temperatures and different focusing distances is evaluated.The software named Advanced System Analysis Program(ASAP)is used to simulate the light transmission of the system.Finally,the system integration and test are carried out.(4)The radiation temperature measurement experiment and analysis of aeroengine turbine blade were carried out.The experimental scheme of turbine blade radiation temperature measurement was designed,and the experimental platform of turbine blade radiation temperature measurement in laboratory environment was built.The radiation temperature of turbine blade surface was measured in the simulated high temperature radiation environment.Compared with the colorimetric method,the average relative measurement error of the three-band radiation thermometry algorithm based on reflection error correction decreases from 2.82% to 1.20%.