Rayleigh–Taylor instability occurs when a heavier fluid overlies a lighter fluid, and the two seek to exchange positions under the effect of gravity. We present a linearized theory for arbitrary three-dimensional (3D) initial disturbances that grow in time, and calculate the evolution of the interface for early times. A new spectral method is introduced for the fully 3D nonlinear problem in a Boussinesq fluid, where the interface between the light and heavy fluids is approximated with a smooth but rapid density change in the fluid. The results of large-scale numerical calculation are presented in fully 3D geometry, and compared and contrasted with the early-time linearized theory.

Item Type:	Refereed Article
Keywords:	viscous flow, Rayleigh-Taylor instability, linearization, spectral method
Research Division:	Mathematical Sciences
Research Group:	Applied mathematics
Research Field:	Theoretical and applied mechanics
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the physical sciences
UTAS Author:	Walters, SJ (Mr Stephen Walters)
UTAS Author:	Forbes, LK (Professor Larry Forbes)
ID Code:	137089
Year Published:	2019
Funding Support:	Australian Research Council (DP140100094)
Web of Science® Times Cited:	3
Deposited By:	Mathematics
Deposited On:	2020-01-30
Last Modified:	2020-05-20
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