scholarly journals On the slow motion of a spheroid in a rotating stratified fluid

2016 ◽  
Vol 808 ◽  
Author(s):  
E. R. Johnson ◽  
Stefan G. Llewellyn Smith
Keyword(s):  
Rossby Wave ◽  
Laboratory Experiments ◽  
Bottom Topography ◽  
Slow Motion ◽  
Flow Patterns ◽  
Stratified Fluid ◽  
Rotating Stratified Fluid ◽  
Oceanic Flows

We consider the slow motion generated when a body is set into motion relative to an incompressible, inviscid, non-diffusive rotating stratified fluid, showing that there is generated in general a topographic Rossby wave which leads to non-decaying fluctuations in the lift on the obstacle and a fluctuating non-zero drag. The problem is relevant to the flow patterns and forces excited when slow oceanic flows cross bottom topography, and suggests a mechanism for slow fluctuations observed in laboratory experiments.

scholarly journals Spin-up of a two-layer rotating stratified fluid in a variable-depth container

2001 ◽  
Vol 438 ◽  
pp. 379-407 ◽  
Author(s):  
R. E. HEWITT ◽  
M. R. FOSTER ◽  
P. A. DAVIES
Keyword(s):  
Laboratory Experiments ◽  
Large Time ◽  
Stratified Fluid ◽  
Variable Depth ◽  
Density Interface ◽  
Fluid Layers ◽  
Boundary Slope ◽  
Slope Discontinuity ◽  
Wall Slope ◽  
Rotating Stratified Fluid

We consider the spin-up of a two-layer, stably (density) stratified fluid in a rotating container with an axisymmetric sloping base and cylindrical walls. Details of the spin- up readjustment mechanisms are presented under the assumption of small impulsive changes in the rotation rate of the container. It is shown that the relative positions of the density interface and the discontinuity in wall slope determine the qualitative large-time spin-up response of the fluid. The density interface leads to a spin-up readjustment in each of the fluid layers that is essentially independent. However, when the density interface is below the boundary-slope discontinuity, a sub-region of the upper layer is predicted to readjust in an algebraic rather than exponential manner. A detailed sequence of laboratory experiments have been performed to confirm the predictions of the linear spin-up analysis.

Shear layers in a rotating stratified fluid with bottom topography

1973 ◽  
Vol 58 (4) ◽  
pp. 677-687 ◽  
Author(s):  
Yves J. F. Desaubies
Keyword(s):  
Bottom Topography ◽  
Side Wall ◽  
Shear Layers ◽  
Stratified Fluid ◽  
Ekman Number ◽  
Column Formation ◽  
Rotating Stratified Fluid ◽  
Taylor Column

The structure of shear layers due to bottom topography in a rotating stratified fluid is obtained under the restriction σS [Lt ] E½, where σS = ναgΔT/KΩ2L is a measure of the stratification and E = ν/Ω2L is the Ekman number. The layers are found to be similar to the side-wall layers discussed by Barcilon & Pedlosky (19673) if σS [Gt ] E½ and are Stewartson layers if $\sigma S \ll E^{\frac{2}{3}}$. Some comments are made on the possibility of Taylor column formation in a stratified fluid.

scholarly journals Instabilities in the spin-up of a rotating, stratified fluid

2010 ◽  
Vol 22 (5) ◽  
pp. 054108 ◽  
Author(s):  
R. J. Munro ◽  
M. R. Foster ◽  
P. A. Davies
Keyword(s):  
Stratified Fluid ◽  
Rotating Stratified Fluid

scholarly journals Observation and analysis of long-periodic modes in a confluence with dominant tributary inflow

2018 ◽  
Vol 40 ◽  
pp. 05043
Author(s):  
Laurent Schindfessel ◽  
Tom De Mulder ◽  
Mia Loccufier
Keyword(s):  
Numerical Simulations ◽  
Secondary Flow ◽  
Significant Influence ◽  
Laboratory Experiments ◽  
Flow Patterns ◽  
Modal Decomposition ◽  
Periodic Oscillations

Confluences with dominant tributary inflow are found to exhibit long-periodic alternations of the flow patterns. They are shown to exist both in laboratory experiments and in numerical simulations. By means of a modal decomposition, insight is given into these long-periodic oscillations. The origin of these oscillations is investigated and their significant influence on the secondary flow patterns in the downstream channel is revealed.

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