NUMERICAL-ANALYSIS OF THE NONSTATIONARY OBLIQUE REFLECTION OF WEAK SHOCK-WAVES

Numerical calculations are performed for the oblique reflection of weak shock waves with finite thickness from a wedge. Three models of broad shock fronts are considered: dispersive waves due to vibrational nonequilibrium in carbon dioxide; and dissipative waves due to real and artificial viscosities in a perfect gas. The two-dimensional Euler and Navier-Stokes equations are solved by using an FCT MacCormack combined method with an operator-splitting technique and a grid generation technique. The results show features common to those three models. In the case of the regular reflection of a shock wave with a discontinuous front (shock Mach number 1.027 and wedge angle 30-degrees), a short stem appears at the foot of the reflected wave and a nonstationary process occurs just after the incident wave passes over the leading edge of the wedge. Furthermore, it is shown that the wave patterns of dispersed irregular reflection can be reproduced by the present numerical simulation, as found in the experimental results.