Mathematical simulation of Mach reflection of shock waves in media with different adiabatic indices

Some peculiarities of the processes of regular and Mach reflection at constant adiabatic index =c_p/c_v=1.4 were investigated theoretically in [1]. It was demonstrated that increase in incident-wave intensity above some value leads to the appearance of an internal compression discontinuity (Fig. 1) and a break in the reflected wave (at point h), both of which had been observed previously only in experiment [2–4]. In the present study the method described in [1] is used to study the influence of adiabatic index on these peculiarities of the Mach reflection process which lead to a significant increase in pressure (to a maximum value P_m) on the surface wedge in the vicinity of point i. Pressure and density curves along the wedge surface are presented. It is found that increase in leads to the same qualitative changes in the pressure and density curves on the surface as are observed upon increase in semiaperture angle of the wedge or upon decrease in Mach number M_f of the shock-wave front incident on the wedge ab. These similarities in the shock-wave reflection process were first noted in [5] for weak shock waves in which the internal compression discontinuity does not appear.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 8, pp. 90–94, May–June, 1976.The author thanks O. S. Ryzhov for the many valuable remarks offered in his evaluation of the study.