A method for selecting the length of the tail jet flow direction test section for infrared radiation testing

Abstract

The invention discloses a method for selecting the length of a tail jet flow direction test section for an infrared radiation test. The method includes the following steps: firstly, a 30m distance marker lamp and a 15m marker point are set; secondly, a mid-wave infrared thermal imager is set; secondly, the engine is tested And use the mid-wave infrared thermal imager to take the infrared heat map of the tail jet: according to the test run process, the test run is carried out, respectively, when the engine is in a typical working state, and after the state is stable for a preset time, use the mid-wave infrared thermal imager to measure the tail jet. The flow is measured to obtain the infrared heat map of each state, after the engine test run is over, the medium-wave infrared thermal imager is turned off, and the cable is disconnected; then the infrared heat map obtained in step 3 is processed to obtain the tail jet infrared radiation field; the present invention uses It is used to assist in determining the measurement distance of the Fourier infrared spectrometer, and meets the needs of using the Fourier infrared spectrometer in the field to test the infrared spectral radiation characteristics of the aeroengine.

Description

technical field [0001] The invention belongs to the field of infrared spectral radiation testing, in particular to a method for selecting the length of a tail jet flow direction test section for infrared radiation testing. Background technique [0002] The aeroengine is an important source of infrared radiation in the tail direction of the aircraft. Measuring its infrared spectral radiation characteristics can provide an important reference for the stealth design of the engine and the evaluation of stealth performance. At present, Fourier transform infrared spectrometers are mostly used for testing the infrared spectral radiation characteristics of the engine tail direction. The Fourier transform infrared spectrometer has the advantages of multi-channel simultaneous measurement, high precision, and high signal-to-noise ratio. However, in the process of testing the infrared spectral radiation characteristics of aeroengines, the field of view is small, and the signal-to-noise ...

AI Technical Summary

Problems solved by technology

The gas infrared radiation intensity of the engine tail jet is much smaller than the solid infrared radiation intensity of the engine inner wall and the central cone. In addition, the Fourier transform infrared spectrometer is placed far away, and the infrared radiation signal is seriously attenuated after being transmitted through the long-distance atmosphere. The signal received by the infrared spectrometer is greatly weakened, and the proportion of background radiation increases, resulting in a decrease in the signal-to-noise ratio, and there are large errors in the measurement results

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