A structural design to reduce growth rate of Rayleigh-Taylor instability

This work investigates applying an initial perturbation into an unstable system in order to increase its stability against perturbations. In the present paper we try to realize such instability suppression by a new technique. We numerically show that by applying a special form of initial perturbation, the instability will grow with slower velocity. In order to do that, a computer code is used to calculate the temporal evolution of perturbed interfaces between two ideal semi-infinite fluids. Then, the evolution of a rectangular perturbation and also a mushroom-like perturbation is investigated. It is shown that mushroom-like perturbation which is a small-scale form of the well-known instabilities (e.g. Raleigh-Taylor and Kelvin-Helmholtz instabilities) has a smaller growth velocity than rectangular one. Such a structural design specially reduces the vortices in the fluids which are responsible for fluids mixing in instabilities. The mushroom-like structure has been selected as it is similar to the initial phase of RTi mushrooms. This structure help to reduce the secondary Kelvin-Helmholtz rotations in the edges of RTi mushrooms. Introduction: