Blast Wave with Variable Energy Through A Rotating Gas

Abstract

Shock phenomenon is one of the most interesting topics in the age of Science and technology. It has many applications not only in different branches of modern science, such as astrophysics, supersonic flights, explosions and plasma physics etc. but also in the field of medical Sciences.

In the study of the propagation of these waves, some assumptions are generally made, for example.

(i)      The energy release is instantaneous.

(ii)     The ambient gas pressure is negligible in comparision with the pressure immediately behind the shock.

(iii)    The fluid is in viscid and non-heat conducting

(iv)    Radiation losses are negligible.

However, in practical problems, these assumptions are only approximately valid and one has often to drop one or more of them depending on the physical situations under study.

Sakurai’s analysis as modified by Freeman to study the propagation of variable energy blast waves through a uniform medium has been extended to include the propagation through a non-uniform medium with particular reference to cylindrical blast wave in a rotating gas. For an energy input E?=E0T?(1+e1w+e2w2+...). Where E? is the energy released upto time t, E0 is a functional contant, ? and e1 e2 etc. are constants and w is non-dimensiona time, it is seen that the effects of non-uniformity caused by solid body rotation of the gas are assentially of third order. Dependence of flow variables on the non-uniformity and the strength of energy iput characterised respectively by the parameter x2 and various e-values has been discussed. It is observed that an increase in the initial angular velocity leads to a decrease in shock velocity.