scholarly journals An experimental study on mixing induced by gravity currents on a sloping bottom in a rotating fluid

2002 ◽  
Author(s):  
Mitchihiro Ohiwa
Keyword(s):  
Experimental Study ◽  
Gravity Currents ◽  
Rotating Fluid ◽  
Sloping Bottom

scholarly journals An Experimental Study on the Growth of Gravity Currents.

1995 ◽  
pp. 15-26
Author(s):  
Kesayoshi Hadano ◽  
Muneo Hirano ◽  
In-cheol Lee ◽  
Yongdi Yang
Keyword(s):  
Experimental Study ◽  
Gravity Currents

Experiments with density currents on a sloping bottom in a rotating fluid

2000 ◽  
Vol 31 (1-4) ◽  
pp. 139-164 ◽  
Author(s):  
D Etling ◽  
F Gelhardt ◽  
U Schrader ◽  
F Brennecke ◽  
G Kühn ◽  
...  
Keyword(s):  
Density Currents ◽  
Rotating Fluid ◽  
Sloping Bottom

An experimental study of unstable barotropic vortices in a rotating fluid

1991 ◽  
Vol 223 (-1) ◽  
pp. 1 ◽  
Author(s):  
R. C. Kloosterziel ◽  
G. J. F. van Heijst
Keyword(s):  
Experimental Study ◽  
Rotating Fluid

scholarly journals Entrainment in a Dense Current Flowing Down a Rough Sloping Bottom in a Rotating Fluid

2017 ◽  
Vol 47 (3) ◽  
pp. 485-498 ◽  
Author(s):  
Luisa Ottolenghi ◽  
Claudia Cenedese ◽  
Claudia Adduce
Keyword(s):  
Laboratory Experiments ◽  
Strong Dependence ◽  
Flow Dynamics ◽  
Shear Instability ◽  
Rotating Fluid ◽  
Ambient Fluid ◽  
Homogeneous Fluid ◽  
Roughness Elements ◽  
Consequent Reduction ◽  
Sloping Bottom

AbstractDense oceanic overflows descend over the rough topography of the continental slope entraining and mixing with surrounding waters. The associated dilution dictates the fate of these currents and thus is of fundamental importance to the formation of deep water masses. The entrainment in a dense current flowing down a sloping bottom in a rotating homogeneous fluid is investigated using laboratory experiments, focusing on the influence of the bottom roughness on the flow dynamics. The roughness is idealized by an array of vertical rigid cylinders and both their spacing and height are varied as well as the inclination of the sloping bottom. The presence of the roughness is generally observed to decelerate the dense current, with a consequent reduction of the Froude number, when compared to the smooth bottom configuration. However, the dilution of the dense current due to mixing with the ambient fluid is enhanced by the roughness elements, especially for low Froude numbers. When the entrainment due to shear instability at the interface between the dense current and the ambient fluid is low, the additional turbulence and mixing arising at the bottom of the dense current due to the roughness elements strongly affects the dilution of the current. Finally, a strong dependence of the entrainment parameter on the Reynolds number is observed.

scholarly journals Buoyant gravity currents along a sloping bottom in a rotating fluid

2002 ◽  
Vol 464 ◽  
pp. 251-278 ◽  
Author(s):  
STEVEN J. LENTZ ◽  
KARL R. HELFRICH
Keyword(s):  
Vertical Wall ◽  
Gravity Current ◽  
Classical Problem ◽  
Propagation Speed ◽  
Gravity Currents ◽  
Scaling Theory ◽  
Bottom Slope ◽  
Dimensional Parameter ◽  
Density Anomaly ◽  
Sloping Bottom

The dynamics of buoyant gravity currents in a rotating reference frame is a classical problem relevant to geophysical applications such as river water entering the ocean. However, existing scaling theories are limited to currents propagating along a vertical wall, a situation almost never realized in the ocean. A scaling theory is proposed for the structure (width and depth), nose speed and flow field characteristics of buoyant gravity currents over a sloping bottom as functions of the gravity current transport Q, density anomaly g′, Coriolis frequency f, and bottom slope α. The nose propagation speed is cp ∼ cw/ (1 + cw/cα) and the width of the buoyant gravity current is Wp ∼ cw/ f(1 + cw/cα), where cw = (2Qg′ f)1/4 is the nose propagation speed in the vertical wall limit (steep bottom slope) and cα = αg/f is the nose propagation speed in the slope-controlled limit (small bottom slope). The key non-dimensional parameter is cw/cα, which indicates whether the bottom slope is steep enough to be considered a vertical wall (cw/cα → 0) or approaches the slope-controlled limit (cw/cα → ∞). The scaling theory compares well against a new set of laboratory experiments which span steep to gentle bottom slopes (cw/cα = 0.11–13.1). Additionally, previous laboratory and numerical model results are reanalysed and shown to support the proposed scaling theory.

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