Non-parallel-flow stability of a two-dimensional buoyant plume

1985 ◽  
Vol 159 (-1) ◽  
pp. 241 ◽  
Author(s):  
Shunichi Wakitani
2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Sandra K. S. Boetcher ◽  
F. A. Kulacki ◽  
Jane H. Davidson

A numerical simulation of transient two-dimensional negatively buoyant flow into a straight baffle situated below an isothermal circular cylinder in an initially isothermal enclosure is presented for both an adiabatic and a highly conducting baffle for Rayleigh numbers from 106 to 107. Results show the effects of baffle offset, width, and length on the point where viscous flow develops and on velocity profiles within the baffle. Results are interpreted to guide the design of straight baffles to reduce destruction of stratification in thermal stores using an immersed heat exchanger. The preferred geometry is a low-conductivity baffle of width equal to the effective width of the heat exchanger and 15 or more cylinder diameters in length to ensure nearly fully developed flow at the baffle outlet.


1975 ◽  
Vol 68 (3) ◽  
pp. 609-624 ◽  
Author(s):  
S. C. Traugott

A two-dimensional horizontal flow is discussed, which is induced by other, buoyancy-driven flows elsewhere. It is an adaptation of the incompressible wall jet, which is driven by conditions a t the leading edge and has no streamwise pressure gradient. The relation of this flow to the classical buoyancy-driven boundary layers on inclined and horizontal surfaces is investigated, as well as its possible connexion with a two-dimensional buoyant plume driven by a line source of heat. Composite flows are constructed by patching various such solutions together. The composite flows exhibit$Gr^{\frac{1}{4}}$scaling (Grbeing the Grashof number).


1968 ◽  
Vol 47 (1-4) ◽  
pp. 32-56 ◽  
Author(s):  
ROBERT C. ACKERBERG ◽  
ALEXANDER PAL

1988 ◽  
Vol 31 (12) ◽  
pp. 3480 ◽  
Author(s):  
Mihir Sen ◽  
P. Vasseur ◽  
L. Robillard

Author(s):  
Xuemin Ye ◽  
Chunxi Li ◽  
Weiping Yan

The temporal stability equation of the two-dimensional traveling waves of evaporating or condensing liquid films falling down an inclined wall is established based on the Prandtl boundary layer theory and complete boundary conditions. By investigating the flow temporal characteristics curves, including the stability curves and stability curves of the fastest wave, the effects on flow stability of evaporating, isothermal and condensing states, thermocapillarity, Reynolds number, fluid property and inclined angle are discussed, and are compared in different Reynolds numbers. The theoretical study indicated that evaporation process destabilizes the film flow and condensation process stabilizes the film flow, the thermocapillarity take a destabilizing effect in evaporation condition and an adverse effect in condensation condition. Present study indicates that the temporal growth rate increases with increase of the Reynolds number and inclination angle, and decreases with increase of Ka numbers. And the effects on flow stability of liquid properties and inclination angle are always significant.


2014 ◽  
Vol 685 ◽  
pp. 232-235
Author(s):  
Ning Kang ◽  
Yuan Cao

In the field of computational fluid dynamics, grid generation costs most of work. The accuracy and reliability of the simulated results depend directly on grid quality. The two dimensional parallel flow with low speed was used to study the effect of grid quality on simulated results. Several conclusions are obtained. The computational error decreases with the increase of domain size in flow direction. Too many grids in flow direction will lead to bigger round-off error, while too few grids will make it harder to catch the correct flow. The increase of grid quantity in the direction perpendicular to flow direction will decrease the computational error, but the effect is not obvious. Increasing the grid quantity in the area near the wall will decrease the computational error.


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