Blast waves in inhomogeneous atmospheres including real gas and heat transfer effects**This paper was presented in its preliminary form as plenary lecture at the GAMM-Conference 1993 in Dresden.

Abstract

The real gas and heat transfer effects, particularly at the early stage of the propagation of a very strong blast wave resulting from a point explosion in an atmosphere whose density varies with altitude, are addressed by numerical computation. The new twist in this classical blast wave problem is that the simplistic perfect gas equation of state is abandoned, and replaced with a set of realistic, albeit approximate equilibrium gas properties, including internal energy for intermolecular forces, vibration, excitation of electrons, dissociation, ionisation and conductive and radiative heat transfer. The whole complex problem is then solved by the method of characteristics. The computations are carried out for blast waves propagating upward and downward in an isothermal atmosphere. The results are compared with results obtained using a perfect gas model. From the comparison it appears that temperature profiles and, accordingly, density profiles are affected most by the real gas.