Turbulent energy at accelerating and shocked interfaces

Abstract

The turbulent energy generated at accelerating or shocked interfaces between two fluids is calculated. Assuming a linear density profile across the mix region it was found that Eturb/Edir=2.3A2% for a constant acceleration and 9.3A2% for a shock, where A is the Atwood number of the two fluids. Somewhat less turbulent energy is generated if density profiles based on self-similar solutions to nonlinear diffusion equations were used. These equations also predict eddy sizes: λ/h=26%–29% and λ/h=16%–18% were found for a constant acceleration and a shock, respectively, where λ is the eddy size controlling the diffusion coefficient and h is the mixing depth into the heavier fluid. The present results were compared with other models and with experiments conducted at AWE.