The evolution of the multimode Rayleigh-Taylor instability of nearly incompressible fluids, with density ratio r = 2, is investigated by means of two-dimensional hydrodynamic simulations. The study focuses on the effect of the initial perturbation on the evolution towards turbulent mixing. It is shown that, for sufficiently large times, a self-similar mixing regime occurs, in which typical spatial scales (such as the size of the mixed layer) evolve proportionally to g(t - t0)2, where g is the gravity, t the time, and t0 is a characteristic time depending on the initial conditions. A model for the prediction of t0 is then presented, which is in agreement with the simulations.
Evolution of Multi-mode Rayleigh-Taylor Instability Towards Self-Similar Turbulent Mixing / Atzeni, Stefano; A., Guerrieri. - In: EUROPHYSICS LETTERS. - ISSN 0295-5075. - STAMPA. - 22:(1993), pp. 603-609. [10.1209/0295-5075/22/8/008]
Evolution of Multi-mode Rayleigh-Taylor Instability Towards Self-Similar Turbulent Mixing
ATZENI, Stefano;
1993
Abstract
The evolution of the multimode Rayleigh-Taylor instability of nearly incompressible fluids, with density ratio r = 2, is investigated by means of two-dimensional hydrodynamic simulations. The study focuses on the effect of the initial perturbation on the evolution towards turbulent mixing. It is shown that, for sufficiently large times, a self-similar mixing regime occurs, in which typical spatial scales (such as the size of the mixed layer) evolve proportionally to g(t - t0)2, where g is the gravity, t the time, and t0 is a characteristic time depending on the initial conditions. A model for the prediction of t0 is then presented, which is in agreement with the simulations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.