Abstract: Numerical simulation, theoretical modeling, and experimental verification was used comprehensively to study the prediction method of gas explosion overpressure in pipelines. It is found that blast wave can be divided into three types, e.g. detonation wave, high speed deflagrate wave, and slow combustion wave. The blast wave reflects the relationship between flame combustion and explosion overpressure. A typical blast wave consists of three parts: front shock wave, flame compression wave, and rarefaction wave. Overpressure of front shock wave increases as explosion propagation, and its relationship with distance can be well characterized by a linear function. The relationship between secondary peak overpressure of the flame compression wave and the propagation distance can also be fitted by a linear function, but its waveform can be characterized by an exponential function. Finally, experiments verify the correctness of the blast waveform function proposed in this paper, which can well predict the evolution of explosion overpressure. The conclusion is basically the same as the numerical simulation. The research results can provide theoretical basis for prediction and damage assessment of explosion overpressure of combustible gas in pipelines or tunnels.

Key words: gas explosion, overpressure, blast waveform, flame, blast wave