Buoyancy-drag mix model obtained by multifluid interpenetration equations

Abstract

In this paper, a buoyancy drag equation for describing the motion of the edges of a mixing zone driven by Rayleigh-Taylor or Richtmyer-Meshkov instabilities is derived from the multifluid interpenetration mix model equations of Scannapieco and Cheng [Phys. Letters A 299, 49 (2002)]. This derivation provides a physics foundation for a large class of phenomenological buoyancy-drag mix models and also establishes a physical connection between the microscopic collision frequency and the macroscopic fluid drag coefficient. The predicted values for model parameter a(ss') in the multifluid interpenetration mix model, from the Rocket-Rig experiments, is in the range of 0.043-0.125 depending upon the Atwood number. The results are also in good agreement with inertial confinement fusion capsule implosions.