Effect of Obstacles Gradient Arrangement on Non-Uniformly Distributed LPG–Air Premixed Gas Deflagration

The arrangement of obstacles can significantly impact the deflagration behavior combustible gases. In actual pipeline accident site, liquefied petroleum gas (LPG) and other gases often show non-uniform distribution after leakage owing to diffusion gravity, mechanism is also more complex. this paper, based on gases, flame overpressure characteristics LPG–air are carried out by a combination experiments numerical simulations with arranged in increasing decreasing blockage height. results that height arrangement, forms “straw hat” cavity, finally forming an elliptical region. appears as “ribbon-shaped” narrow, blank area, which gradually becomes longer time. By observing structure propagation coupled state, it found explosion maximum when obstacle consistent, moment area slightly earlier than appearance peak. At same time, without considering change obstacle, three arrangements all have accelerating effect deflagration. And condition has most obvious acceleration, makes peak appear at first, leads formation positive feedback among speed propagation, overpressure. addition, case acceleration obtained initial stage very important for overall flame. paper provide reference placement equipment facilities long narrow spaces such various pipe galleries, make predictions about shape some objects theoretical basis prevention management explosions.