IMPACT OF THERMAL DISPERSION DURING FORCED CONVECTION CONDENSATION IN A THIN POROUS*/FLUID COMPOSITE SYSTEM
Title:
IMPACT OF THERMAL DISPERSION DURING FORCED CONVECTION CONDENSATION IN A THIN POROUS*/FLUID COMPOSITE SYSTEM
Author:
Renken, K. J. Meechan, K.
Appeared in:
Chemical engineering communications
Paging:
Volume 131 (1995) nr. 1 pages 189-205
Year:
1995-01-01
Contents:
The effect of thermal dispersion during laminar forced convection filmwise condensation within a thin porous/fluid composite system is examined numerically. The model simulates two-dimensional condensation within a very permeable and highly conductive thin porous-layer coated surface. The local volume-averaging technique is utilized to establish the energy equation and to account for the thermal dispersion effect. The Darcy-Brinkman-Forchheimer model is employed to describe the flow field in the porous layer while classical boundary layer equations are used in the pure condensate region. The numerical results, which detail the dependence of the heat transfer rate and temperature field on the governing parameters (e.g., Reynolds number, Rayleigh number, Darcy number, Prandtl number, thermal dispersion coefficient, as well as porous coating thickness and thermal conductivity ratio), are calculated using a finite difference scheme. It is found that due to the better mixing of the thermal dispersion effect, the heat transfer rate is greatly increased and the effect becomes more pronounced as the Reynolds number increases. The results of this study provide valuable fundamental predictions of enhanced film condensation that can be used in a number of practical thermal engineering applications.
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