Measurement Method of Combustion Instability Test in Combustion Chamber Based on Image Processing

Abstract

The invention discloses a combustion chamber combustion instability test measuring apparatus and method based on image processing. The apparatus comprises a combustion chamber, a high-frequency pressure transducer or a microphone, an acquisition card, a charge amplifier, a computer and a high-speed photographic instrument, the high-frequency pressure transducer or the microphone measures pressure pulsation signals in the combustion chamber in real time, the acquisition card acquires the measured pressure pulsation signals in the combustion chamber, the charge amplifier amplifies the pressure pulsation signals and transmits the pressure pulsation signals to the computer, and the high-speed photographic instrument or another high-speed CCD camera performs high-frequency shooting on a flame change process in the combustion chamber. By employing the combustion instability test measuring method based on image processing, test measurement of the combustion instability in the combustion chamber can be performed, the generation reasons of the combustion instability thereof can be preliminarily obtained, and the problem of combustion instability in the combustion chamber can be solved by employing an active or passive suppression method.

Description

technical field [0001] The invention belongs to the field of gas turbines and aeroengines, and relates to an image processing-based combustion instability test method for combustion chambers. Background technique [0002] In order to reduce the emission of combustion pollutants, lean oil premixed pre-evaporative combustion technology is generally used in the design of combustion chambers, whether it is the combustion chamber of civil aircraft aeroengine or ground gas turbine combustion chamber. In the design of lean-oil premixed pre-evaporation low-pollution combustors, the most likely problem is combustion instability. At the same time, combustion instability is also prone to occur in the afterburner of aero-engines and the combustion chamber of rocket engines. When combustion instability occurs in the combustion chamber, the strong pressure pulsation may cause the vibration of the combustion chamber and even the entire engine to intensify, make a huge combustion noise, an...

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Problems solved by technology

However, the biggest difficulties of this test measurement method are as follows: 1) The main frequency of combustion instability is generally relatively large, several hundred hertz, and to explain the mechanism of combustion instability, it is necessary to measure at least 10 or more within a pulsation cycle In order to explain the relationship between the combustion heat release rate and the vortex structure of the transient flow field within a pulsation cycle, the response frequency of test equipment such as planar laser-induced fluorescence (PLIF) and particle image velocimetry (PIV) must reach at least Above 1000HZ, so the requirements for measuring equipment are high, and the response frequency of domestic PLIF is generally tens of hertz, so it cannot meet the current measurement requirements; 2) It is necessary to measure the transient heat release rate and flow field vortex structure at the same time at the same phase, Phase synchronization is required for planar laser-induced fluorescence and particle image velocimetry, which is very difficult in practical experimental measurements

Therefore, the above research methods have certain limitations in the process of studying the combustion instability mechanism. This project proposes a novel combustion instability test measurement method, which is convenient for measurement and simple equipment

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