Investigation of solid structure obstacles influence on flame propagation in semi-open tube

By means of applying self-designed experimental system for flame acceleration, the paper investigated solid structure, blockage ratios, spatial layout and ignition distance of obstacles influence on flame speed and overpressure. In the experiments, five kinds of obstacles (plates, cuboids, triple prisms, quadruple prisms and cylinders) were adopted with three kinds of blockage ratios (20%, 40% and 60%). For the same blockage ratios, results demonstrated that plates and triple prisms increased flame speed and overpressure much larger. cuboids were intermediate while effect of quadruple prisms and cylinders were comparatively limited. When obstacles were put in the place to form bifurcation channel, which would lead to flame speed and overpressure rose rapidly. Flame speed and overpressure at first increased and then minished with the augument of ignition distance. When obstacles were put at L/S≈6.5(length/side), fla me speed and overpressure were much influenced. flame speed was affected larger than overpressure in all above condition. The results were expected to have some help on preventing and controlling gas explosive and to provide reference for industry safety design.