Quasi universal blast wave behavior

Abstract
The two major parameters of shock wave propagation in free air are the space-time diagram and the decay of the peak overpressure as a function of the radial distance. This paper proposes a very simple mathematical function which simulates the space-time diagram and then correlates the peak overpressure. Various applications are presented that validate the proposed functions. In the far field, the asymptotic behaviour is consistent with the physical phenornenon and the similitude laws are preserved. In this manner, the quasi-universal behaviour of shock wave propagation in free air is demonstrated. Very easy-to-use, the proposed functions appear as quasi-universal ones.