(a) Time–distance plot of the normalized longitudinal velocity, v_z. It can be seen that the gas-dynamic shock remains stationary until propagating fast shocks form. Here, the shock is impelled along the z-direction by each shock that “hits” the gas-dynamic shock. (b) The flow speed upstream of the shock (z = 0.3) decreases as it is converted into twisting motions. Panel (c) shows the flow speed at z = 0.99.

(An animation of this figure is available.)

The video/animation of this figure is available in the online journal.