High-resolution Euler simulation of a cylindrical blast wave in an enclosure

We solve the Euler equations to simulate a cylindrical blast wave in an enclosure. The blast is initiated close to the bottom wall of a square enclosure. An initial Mach 10 shock wave moves into ambient air, causing a mushroom structure behind the shock. We relate the development of this structure to the passage of the reflected shock from the bottom wall through the core of low-density air, which appears to trigger the Richtmyer–Meshkov instability. Use of a ninth-order derivative formula with a four-stage third-order Runge–Kutta time stepping scheme allows us to visualize the vortical motion at the core of the blast in great detail, including the spikes of ambient air penetrating the blast core and two symmetric trails of small-scale vortices behind the primary vortices