Propagation characteristics of gas explosion in duct with sharp change of cross sections

To master the propagation characteristics of gas explosion in duct with sharp change of cross sections, the explosion wave overpressure and flame velocity of gas explosion in duct with sharp change of cross sections are measured by means of experiment in this paper and the propagation law is theoretically analyzed and numerically simulated. In duct with sharp change of cross sections, the reflux is formed, turbulence intensity and flame combustion velocity all increase. It is shown that the effect of sharp change of cross sections on the flame velocity and overpressure is obvious and the destruction in ended duct surface is especially serious. So during the mine exploitation and laneway design, the laneway with sharp change of cross sections should be avoided and the obstruction should be eliminated as far as possible. When the sharp change of cross sections is unavoidable, the relevant preventive measures should be adopted to suppress the gas explosion propagation, depress the intensity and diminish the loss due to gas explosion, according to the propagation rules.