Navier-Stokes Calculations of Argon Shock Wave Structure

Abstract

The classical Navier-Stokes theory was used to calculate profiles of plane shock waves in argon. The viscosity-temperature relationship employed in the calculation was based on a Lennard-Jones 6–12 intermolecular potential function for which the parameters were derived from experimental viscosity measurements up to 1100°K. With this viscosity function, the maximum-slope shock thicknesses obtained were smaller than previously calculated assuming viscosity proportional to T0.816. Also it was found that the maximum-slope thickness based on the density profile was less than that based on the velocity profile. The density profile thicknesses calculated with the Lennard-Jones viscosity function were the same order of magnitude as, but not in quantitative agreement with experimental density thicknesses obtained with the optical reflectivity technique. It was found that Navier-Stokes profiles become asymmetric as the shock strength is increased. However, the calculated asymmetry would have a negligible effect on thickness measurements by the optical reflectivity method.