A two-dimensional numerical model has been developed for studying flows in enclosures having a large length-to-depth ratio. The model solves the two-dimensional Navier-Stokes and energy equations ...subject to hydrostatic, Boussinesq, and rigid-lid assumptions. Turbulent momentum and heat diffusion are incorporated using variable eddy coefficients. The flow is driven by surface wind shear and heat transfer. Two cases were run for a rectangular domain, subject to a suddenly imposed surface shear stress while the surface and bottom were maintained at two different but constant temperatures. The difference between the cases was the formulation used for predicting the eddy viscosities and diffusivities. The variations of velocities and temperatures with time were studied. Both velocities and temperatures were found to undergo a sudden rapid change, after an initial period of slow change, before attaining steady stage. This has been explained in light of the differences in the convective and diffusive time scales and the nature of coupling between the governing equations.
Globalisation and the state Doornbos, Martin; Seethi, K M; Seth, Sanjay ...
Indian journal of political science,
09/2001, Volume:
62, Issue:
3
Journal Article
Viscous fingers have been produced in the lifting Hele-Shaw cell, with
concentric circular grooves etched onto the lower plate. The invading fluid
(air) enters the defending newtonian fluid - olive ...oil as fingers proceeding
radially inwards towards the centre. The fingers are interrupted at the
circular groove, and reform as secondary fingers. The effect of the grooves is
to speed up the fingering process considerably and the fingers now reach the
centre much faster. We explain this by comparing the variation in velocity of
the fingers in the normal HS cell and the grooved cells with time. In the
normal HS cell the fingers move fastest on initial formation and slow down
later. Since in case of the grooved plate, the fingers reform and receive a
boost in their speed each time they encounter a groove, the fingers proceed to
the centre faster. PACS nos. 47.20.Gv, 47.54.+r, 68.03.-g
Viscous fingers have been produced in the lifting Hele-Shaw cell, with concentric circular grooves etched onto the lower plate. The invading fluid (air) enters the defending newtonian fluid - olive ...oil as fingers proceeding radially inwards towards the centre. The fingers are interrupted at the circular groove, and reform as secondary fingers. The effect of the grooves is to speed up the fingering process considerably and the fingers now reach the centre much faster. We explain this by comparing the variation in velocity of the fingers in the normal HS cell and the grooved cells with time. In the normal HS cell the fingers move fastest on initial formation and slow down later. Since in case of the grooved plate, the fingers reform and receive a boost in their speed each time they encounter a groove, the fingers proceed to the centre faster. PACS nos. 47.20.Gv, 47.54.+r, 68.03.-g
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