On the slumping of high Reynolds number gravity currents in two-dimensional and axisymmetric configurations

Ungarish, Marius; Zemach, T.

doi:10.1016/j.euromechflu.2004.05.006

Cited by 41 publications

(59 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Main parameters are presented in the non-dimensional form by adopting the following dimensionally independent scales, in accordance with previous studies [25,36,60], namely lock length x 0 (cf. Fig.…”

Section: Experiments Descriptionmentioning

confidence: 84%

Dynamics of the head of gravity currents

et al. 2013

View full text Add to dashboard Cite

The present work experimentally investigates the dynamics of unsteady gravity currents produced by lock-release of a saline mixture into a fresh water tank. Seven different experimental runs were performed by varying the density of the saline mixture in the lock and the bed roughness. Experiments were conducted in a Perspex flume, of horizontal bed and rectangular cross section, and recorded with a CCD camera. An image analysis technique was applied to visualize and characterize the current allowing thus the understanding of its general dynamics and, more specifically, of the current head dynamics. The temporal evolution of both head length and mass shows repeated stretching and breaking cycles: during the stretching phase, the head length and mass grow until reaching a limit, then the head becomes unstable and breaks. In the instants of break, the head aspect ratio shows a limit of 0.2 and the mass of 123Environ Fluid Mech the head is of the order of the initial mass in the lock. The average period of the herein called breaking events is seen to increase with bed roughness and the spatial periodicity of these events is seen to be approximately constant between runs. The rate of growth of the mass at the head is taken as a measure to assess entrainment and it is observed to occur at all stages of the current development. Entrainment rate at the head decreases in time suggesting this as a phenomenon ruled by local buoyancy and the similarity between runs shows independence from the initial reduced gravity and bed roughness.

show abstract

Section: Experiments Descriptionmentioning

confidence: 84%

Dynamics of the head of gravity currents

et al. 2013

View full text Add to dashboard Cite

show abstract

“…The first interesting work is that of Rottman & Simpson (1983), focused on 2D gravity currents. Since then, this approach has been giving interesting results, as the works of Bonnecaze et al (1993), Klemp et al (1994), D'alessio et al (1996), Ungarish & Zemach (2005) and Ungarish (2007a) show. The approach based on the vertically averaged equations has been successfully applied to gravity current realized in axisymmetric domains (Hallworth et al, 2003;Ungarish, 2007b;Ungarish, 2010) and to fully 3D gravity currents (La Rocca et al, 2008).…”

Section: Introductionmentioning

confidence: 95%

“…Thirdly, the presence of the pressure P s represents a non trivial problem in solving the equations (11). Indeed, while in the 2D and axisymmetric cases the pressure P s can be easily eliminated from the motion equations (Rottmann & Simpson, 1983;Ungarish & Zemach, 2005), for the general case presented here this is not possible. The pressure P s must be determined solving the motion equations together with a specific equation, which can be obtained starting from the following observation: the vector field U { } ( )…”

Section: The Case Of Two Immiscible Liquids With Constant Densitymentioning

confidence: 99%

“…It is assumed that (Pratson et al, 2001;Kostic and Parker, 2007) the heavier liquid is a mixture made with a uniform sediment, characterized by a median diameter d s , with depth averaged concentration C, flowing under an infinite layer of water. This latter assumption is very important, because it is possible to show that, as a consequence of it (Ungarish & Zemach, 2005;La Rocca & Bateman, 2010), the pressure P s vanishes and the motion of the upper layer becomes negligible. Then the well known one layer formulation is obtained for the turbidity current and a considerable reduction of the equations number follows, because only the mass and momentum balance equations of the turbidity current have to be considered.…”

Section: The Case Of Two Liquid Layers With Variable Densitymentioning

confidence: 99%

“…The seminal work of Benjamin (1968) formulates a fundamental theory, based on the perfect-fluid hypothesis and simple extensions of it (like the classical theory of hydraulic jumps), which gives a relationship between the thickness of the gravity current and the velocity of the front. The Benjamin's theory is a milestone and analytical investigations on gravity currents, even the most recent (Shin et al, 2004;Lowe et al, 2005;Ungarish & Zemach, 2005;Ungarish, 2008;Ungarish, 2009) cannot disregard it. Laboratory gravity currents can be realized in very different ways (Simpson, 1997), depending on which features have to be investigated.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental and Theoretical Modelling of 3D Gravity Currents

Rocca¹,

Bateman²

2010

Numerical Simulations - Examples and Applications in Computational Fluid Dynamics

View full text Add to dashboard Cite

Dynamics of Gravity Currents in the Presence of Surface Waves

2018

View full text Add to dashboard Cite

The gravity current dynamics in the presence of regular surface waves is investigated experimentally. The aim is to determine the influence of the wave‐induced velocity field on gravity current kinematic parameters and on the concentration distribution. In the presence of surface waves, the front shows a pulsating behavior while periodic oscillations are observed at the interface between lighter and denser fluids. The dynamics of such processes is related to the wave parameters. Present results confirm that the lock‐exchange generated front velocity is strongly influenced by the oscillatory motion and it may be increased or decreased depending on the Lagrangian mass transport induced by the surface waves. Compared to the propagation in the absence of waves, the dynamics of the concentration field is governed by an enhancement of mixing process due to the orbital motion.

show abstract

On the slumping of high Reynolds number gravity currents in two-dimensional and axisymmetric configurations

Cited by 41 publications

References 19 publications

Dynamics of the head of gravity currents

Dynamics of the head of gravity currents

Experimental and Theoretical Modelling of 3D Gravity Currents

Dynamics of Gravity Currents in the Presence of Surface Waves

Contact Info

Product

Resources

About