Long-lasting effect of initial configuration in gravitationalspreading of material fronts

Nadim Zgheib (1, 2) , Thomas Bonometti (2) , Sivaramakrishnan Balachandar (1)

1 UF - University of Florida [Gainesville]
2 IMFT - Institut de mécanique des fluides de Toulouse

We present the results from laboratory experiments and fully resolved simulations pertaining to finite-release turbulent density flows with a non-axisymmetric initial shape. First, we demonstrate that the effects of the initial shape influence the current’s evolution well into the long-time phase which would corresponds to the inertial self-similar phase in the case of planar or axisymmetric configurations. Then, we identify the physical mechanisms responsible for this dependence and propose a new model capable of capturing the dynamics of such releases. Finally, we show that this dependence on the initial configuration is robust for various types of gravity currents over a wide range of parameters such as Reynolds number, density ratio, and aspect ratio.

Mots clés: Density currents; Gravity currents; Buoyancy-driven flows; Box model; Spectral methods

Domaines: Dynamique des Fluides [physics.flu-dyn]

Nadim Zgheib, Thomas Bonometti, Sivaramakrishnan Balachandar. Long-lasting effect of initial configuration in gravitationalspreading of material fronts. Theoretical and Computational Fluid Dynamics, 2014, vol. 28, pp. 521-529. ⟨10.1007/s00162-014-0330-9⟩. ⟨hal-01096696⟩