Based on high-speed synchronous acquisition of flame dynamic propagation and overpressure signal

an experimental study on the coupled relationship between flame shape and overpressure of gas explosion under different conditions was performed.The experimental results showed that if there was no obstruction

flame front was always relatively smooth and its shape gradually developed into a finger-like shape from initial hemisphere appearance

generating a peak overpressure of 3.9 kPa.If there were central continuous obstacles

flame front changed into a tongue-like shape

and finally into wave-like shape

resulting in a peak overpressure of 12.5 kPa.With continuous obstacles on both left and right walls

flame front gave rise to a mushroom-like shape and at last to Christmas tree shape

producing a peak overpressure of 11.4 kPa.Once flame shape was folded or curled

flame surface area increased and then the burned and unburned gas mixtures were blended rapidly

so that combustion reaction rate and overpressure increased.Furthermore

a theoretical analysis clarified the interaction between flame shapes with transient overpressure.