Abstract
To reveal the inner mechanism of gas explosion dynamic behavior affected by gas equivalent concentration, a high speed Schlieren image system and flow field measurement technology was applied to record the gas explosion flame propagation and flame structure transition. The results show that a flame front structure transition occurs, followed by a flame accelerating propagation process. The laminar to turbulence transition was the essential cause of the flame structure changes. The laminar flame propagation behavior was influenced mainly by gas expansion and fore-compressive wave effect, while the turbulent flame speed mostly depended on turbulence intensity, which also played an important role in peak value of the explosive pressure and flame speed. On the condition that the laminar-turbulent transition was easier to form, the conclusion was drawn that, the lowest CH4 concentration for maximum overpressure can be obtained, which was the essential reason why the ideal explosive concentration differs under different test conditions.
Highlights
It is well known that methane gas has become one of the most important alternative fuels, that is found hidden in coal seams in an adsorption state
Flame Structure Characteristic Based on High Speed Schlieren Photographs
The change of flow field density shows the influences of temperature, concentration and flow field pressure on the flame structure
Summary
It is well known that methane gas has become one of the most important alternative fuels, that is found hidden in coal seams in an adsorption state Nowadays it is widely used as a civil fuel, industrial fuel, power generation fuel, automobile fuel and chemical raw material, to which great attention has been paid by almost all the countries in the World. Studies show that the equivalence ratio is one of primary factors affecting the process and characteristics of CH4 gas combustion and explosions, which influences the flame propagation behavior and the flow field structure through the chemical reaction and the energy release process steps, such as flame acceleration, flame structure and instability and flow behavior [7,8,9,10,11]. According to the acceleration mechanism, acceleration happens due to the initial ignition geometry in the tube axis when a flame develops into a finger-shaped front, with surface area growing exponentially in time
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
