Scaling law of flame propagation velocity and blast pressure in hydrogen-air deflagration

A scaling model for deflagrative blast decay is developed based on the Strhelow's constantvelocity flame model and the field experimental records of pressure transducers and high-speed video images of spherical flames in hydrogen-air clouds. The model provides a scaling rule in which the blast over-pressure normalized by the observed flame propagation velocity decays inversely proportional to the 0.73 power of the distance normalized by the characteristic explosion length. A similar decay behavior is also obtained for the normalized positive impulse. The impulse decay curves for lean and rich gas mixtures do not coincide, although the decay rates are close values.