Mixed Layer Development in a Double-Diffusive, Thermohaline System

1981 ◽  
Vol 103 (4) ◽  
pp. 351-359 ◽  
Author(s):  
C. J. Poplawsky ◽  
F. P. Incropera ◽  
R. Viskanta
Keyword(s):  
Salt Concentration ◽  
Concentration Distribution ◽  
Mixing Layer ◽  
Diffusion Region ◽  
Uniform Temperature ◽  
Uniform Heating ◽  
Interfacial Boundary ◽  
Layer Development ◽  
Double Diffusive ◽  
Heating From Below

A double-diffusive, thermohaline system has been studied under laboratory conditions involving uniform heating from below. Shadowgraph visualization has been used with temperature and salt concentration measurements to investigate mixing layer development and the onset of diffusion layer instabilities. Such instabilities were observed to occur in two of the experiments and were approximately predicted by an existing stability criterion. Interfacial boundary layers which separated the mixing layers from the diffusion region ranged in thickness from 10 to 30 mm and were characterized by a nearly uniform temperature and a nonlinear vertical salt concentration distribution. The rate of mixing layer development decreased with increasing salt concentration.

Interferometric study of stable salinity gradients heated from below or cooled from above

1982 ◽  
Vol 116 ◽  
pp. 411-430 ◽  
Author(s):  
W. T. Lewis ◽  
F. P. Incropera ◽  
R. Viskanta
Keyword(s):  
Mixed Layer ◽  
Mixing Layer ◽  
Density Distributions ◽  
Salinity Gradients ◽  
Isothermal Boundary ◽  
Secondary Layer ◽  
Constant Heating ◽  
Mixed Layers ◽  
Layer Development ◽  
Heating From Below

Mixing-layer development is investigated in laboratory experiments of salt-stratified solutions which are cooled from above or heated from below through the imposition of isothermal boundaries. A Mach-Zehnder interferometer is used to infer salt and density distributions within stable regions of the solution and to determine the extent of mixing-layer development. In both heating from below and cooling from above, this development differs significantly from that which has been observed for constant heating from below. Although the formation of a secondary mixed layer is observed, it does not lead to the development of additional mixed layers. Instead, the secondary layer eventually recedes, and the existence of a single mixed layer is restored. This behaviour is due to the isothermal boundary and the effect which it has no decreasing the heat transfer to or from the solution with increasing time. Once the condition of a single mixed layer is restored, extremely large (stable) density gradients develop in the boundary layer separating the mixed and stable regions, and subsequent growth of the mixed layer is slow. In cooling from above, mixing-layer development depends strongly on whether the isothermal boundary is in direct contact with the solution or separated by an air space.

Modelling temperature and salt concentration distribution in membrane distillation feed channel

Desalination ◽  
2003 ◽  
Vol 157 (1-3) ◽  
pp. 315-324 ◽  
Author(s):  
Maksym N. Chernyshov ◽  
G. Wytze Meindersma ◽  
André B. de Haan
Keyword(s):  
Salt Concentration ◽  
Concentration Distribution ◽  
Membrane Distillation ◽  
Feed Channel

Ejector primary nozzle steam condensation: Area ratio effects and mixing layer development

2014 ◽  
Vol 71 (1) ◽  
pp. 519-527 ◽  
Author(s):  
Kavous Ariafar ◽  
David Buttsworth ◽  
Navid Sharifi ◽  
Ray Malpress
Keyword(s):  
Mixing Layer ◽  
Area Ratio ◽  
Steam Condensation ◽  
Layer Development

scholarly journals A method of designing equipment for heat processing of polymer workpieces

2021 ◽  
Vol 2094 (2) ◽  
pp. 022016
Author(s):  
A O Glebov ◽  
S V Karpushkin
Keyword(s):  
Temperature Field ◽  
Parametric Optimization ◽  
Heat Processing ◽  
Uniform Temperature ◽  
Heating Equipment ◽  
Uniform Heating ◽  
Rubber Mixture ◽  
Second Stage ◽  
Sequential Solution ◽  
Uniform Temperature Field

Abstract The paper describes a method of designing heating equipment that maintains a predetermined temperature field. The method consists in sequential solution of two problems. At the first stage, the heat generation field was calculated using the stationary heat conduction equation. At the second stage, parametric optimization of the temperature field was performed with reference to the power and configuration limits of the heaters. To test this method, the problem of maintaining a predetermined non-uniform temperature field was solved. A practical example of the application of the method for designing a uniform heating plate used in vulcanizing presses was given. To assess the efficiency of the plate, the results of modeling the heat processing of a workpiece from a rubber mixture were presented.

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