Study on statistical invariance of probability processing and fluctuation characteristics of consecutive images of horizontal spray flame under low-pressure

Abstract

With the development of the plateau environment, to make better use of the heat energy and safety of combustion devices, the structure and stability evaluation of horizontal jet flame and other related issues have attracted more and more people's attention. Consecutive image processing of flame is one of the emerging methods to evaluate the flame structure. In this paper, the statistical invariance of horizontal spray flame under low pressure is investigated experimentally and photographically, especially the characteristic of flame terminal fluctuation. A consecutive flame image of 0.05 MPa atmospheric pressure taken by conventional 25 frames per second in a low-pressure chamber was processed with probabilistic statistics, and the probability statistical contours were obtained by binarization statistics for the consecutive 100 to 1000 frames. The results show that different flame characteristic parameters have a different minimum statistical threshold, but most of them are between 300 and 400. The most reasonable statistical interval is determined by combining it with the flame stability evaluation index. The variation mechanism and feasibility of using statistical invariance to characterize flame stability are illustrated from the viewpoint of flame fluctuation characteristics. This is of great significance to the integrity of probabilistic processing of horizontal jet flame and lays a theoretical foundation for flame stability evaluation.