Publication Date:
1998-01-01
Description:
In this paper, numerical and experimental approaches are applied to analyse the dynamics of the front of a gravity current. This study focused on two parameters: internal density and velocity fields. The salt concentration was determined by a potentiometric process. The internal velocities were determined using an optical device and an image-processing system. The structure of the head of the gravity current was analysed. Its density was measured and two stages of evolution were observed. This analysis allows us to coufirm the existence of two important stages. For xf 〈 xs, where the dynamics depend on the initial condition, the flow consists of a head and body and the front density is constant. For xf 〉 xs, we show that the density of the front decreases and evolves towards the Hallworth and others (1993) law. From a comparison between the experiments and the numerical model, we show that the numerical model, which is based on Navier–Stokes equations and on the k−L turbulence model (where L is the height of the gravity current), can predict well flow in the slump regime and in the inertia–buoyancy regime with smoothed results in the transition from the head to the body of the gravity current.
Print ISSN:
0260-3055
Electronic ISSN:
1727-5644
Topics:
Geography
,
Geosciences
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