Measuring device and method for visualizing propagation state and characteristics of high-speed deflagration waves

Abstract

The invention provides a measuring device for visualizing the propagation state and characteristics of high-speed deflagration waves, which comprises a streak window arranged on the side wall of a shock tube of a shock tube experimental platform, a pair of primary mirrors arranged on the two sides of the streak window, a high-frequency LED light source arranged on the upstream of a light path of the primary mirrors, a high-speed camera arranged on the downstream of the light path of the primary mirrors, and a digital delay generator connected with the high-frequency LED light source and the high-speed camera. The invention further provides a corresponding measuring method. The measuring device comprises a signal triggering system connected with the LED light source and the high-speed camera, so that the flash frequency of the light source is synchronous with the shooting frequency of the high-speed camera, and the whole process of detonation wave propagation can be captured. The device is simple in composition and good in operability, and the capturing difficulty of high-speed deflagration waves in the schlieren experiment is reduced.

Description

technical field [0001] The invention belongs to the technical field of deflagration experiments, and in particular relates to a measuring device and method for visualizing the propagation state and characteristics of high-speed deflagration waves. Background technique [0002] A deflagration wave is a burning wave that travels at subsonic speed. It is widely used in the fields of daily industrial production safety and power propulsion. Due to its strong instability, deflagration can easily transition to detonation through the DDT (deflagration-to-detonation) process, thus becoming a research hotspot in the field of combustion and detonation physics. The composition of the deflagration wave can be briefly described as a coupling structure of leading shock wave-induction zone-flame surface. Generally, with the self-acceleration of the flame, the intensity of the leading shock wave will become stronger due to the acceleration of the combustion rate and the increase of heat re...

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Problems solved by technology

[0004] The disadvantage of the existing technology is: the data measurement method lacks an intuitive understanding of the evolution of the deflagration wave during the propagation process, and can only reproduce the state changes during the deflagration wave propagation through the captured real-time pressure / light signals; The same is true for the trace method, which analyzes the morphological evolution of the combustion wave during the propagation process by analyzing the specific structural "cell" shape left on the smoked foil during the propagation of the combustion wave

High-frequency lasers are generally used at home and abroad, but the lasers are expensive and cumbersome; the use of incandescent lamps as light sources is only suitable for the visualization of low-speed flame wave propagation, and the flame propagation speed is mostly around 100m / s, while for high-speed deflagration waves , especially when the flame propagation speed is above 500m / s, the incandescent lamp as the light source will cause the camera to overexposure and the shooting effect will not be good

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