The D'yakov-Kontorovich instability of shock waves in real gases

In the 1950s, D'yakov and Kontorovich predicted that under certain conditio ns perturbed shock waves in nonideal gases can become unstable by emitting undamped sound and entropy-vortex waves. For the last 45 years, though, lit tle progress has been made in the identification and numerical modeling of physical conditions for which this phenomenon might occur. Using a van der Waals equation of state, we present for the first time a dynamical simulati on of a D'yakov-Kontorovich instability. The two-dimensional emission patte rn of acoustic waves appearing in the simulation agrees with the prediction of a linearized theory.