Shock propagation in a driven hard sphere gas: molecular dynamics simulations and hydrodynamics

The continuous injection of energy at a localized region in space in a stationary gas creates a shock wave that propagates radially outwards. We study the hydrodynamics of this disturbance using event driven molecular dynamics of a hard sphere gas in three dimensions, the numerical solution of the Euler equation with a virial equation of state for the gas, and the numerical solution of the Navier-Stokes equation. We show that the results from the Euler equation do not agree with the data from hard sphere simulations. Including dissipative terms through the Navier-Stokes equation results in reasonably good description of the data, when the coefficients of dissipation are chose parametrically.