On bubble and spike oscillations in a dusty gas Rayleigh-Taylor instability

Abstract

AbstractThe Multiphase Buoyancy-Drag model recently formulated in Balakrishnan & Menon, Laser and Particle Beams, 2011 is applied to investigate the (1) rise of dusty gas Rayleigh-Taylor bubbles into a pure gas and (2) fall of pure gas Rayleigh-Taylor spikes into a region of particles. It is demonstrated that for these two scenarios, the bubble or spike amplitude oscillates about the dusty gas/pure gas interface. The ratio of the bubble or spike amplitudes on the pure gas side to the dusty gas side, asymptotes to a constant that depends only on the initial Atwood number, A, the multiphase Atwood number, Am, and the initial wavelength of the perturbation, λo. For the same Am, the ratio decreases with A for oscillating bubbles, and vice versa for oscillating spikes.