Multiphase effects on spherical Rayleigh-Taylor interfacial instability

Abstract

A spherical shock-tube model is implemented to focus the attention on the flow instability produced by the release of the driver mixture of gas-particles into the cold driven pure gas. Four discontinuous spherical surfaces are produced which are in order from outward to inward the Primary Shock, gas Contact Interface, Particle Interface, and Secondary Shock. An appropriate methodology is developed to capture the base flows and the physics of Rayleigh-Taylor-based instabilities. The interaction forces between the two phases and the heat transfer are modeled for both the base and the perturbation flows. The parametric space is explored by varying the particle characteristics in order to reveal the mechanisms involved. The results indicate that the gas-gas contact interface remains unstable for the multiphase cases; however, the growth rate of the instability is dampened due to the inclusion of the particles. Results are compared with theoretical models to explain the mechanisms involved.