Characteristics of Flow and Heat-and-Mass Transfer in a Falling Liquid Film With Three-Dimensional Interfacial Waves

2002 ◽  
Author(s):  
Takao Nagasaki ◽  
Hirokuni Akiyama ◽  
Hiroshi Nakagawa ◽  
Yutaka Ito
Keyword(s):  
Mass Transfer ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Mass Transfer Rate ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Large Wave ◽  
Calculated Mass ◽  
Dimensional Wave

Numerical simulations have been made on the flow and heat-and-mass transfer in a laminar liquid film falling down along a vertical wall by using a boundary-fitted coordinate system. The development of a two-dimensional wave was successfully predicted, which consists of a large solitary wave and ripple waves in front of it. In the large wave a circulating flow exists, and the heat and mass transfer is enhanced by the wave. Further, it was shown by a three-dimensional calculation that a two-dimensional wave becomes unstable with the increase of Re number, resulting in U-shaped three-dimensional wave. The mass transfer rate increases with the transition from two-dimensional to three-dimensional waves. The calculated mass transfer coefficient roughly agrees with empirical correlations.

Three-Dimensional Study of Heat and Mass Transfer in a Partially Porous Elongated Cavity

2010 ◽  
Vol 297-301 ◽  
pp. 728-732
Author(s):  
N. Mimouni ◽  
Salahs Chikh ◽  
Rachid Bennacer
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Cooling System ◽  
Mass Transfer Rate ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Geometrical Parameters ◽  
Computational Domain ◽  
Adsorption Cooling System

A 3D numerical analysis is carried out to investigate heat and mass transfer in a partly porous cavity of high aspect ratio. The goal is to determine the best physical and geometrical parameters that allow optimal heat and mass transfer rate in such domain used in a solar adsorption cooling system. The computational domain consists of a tall cavity heated on the left vertical wall and cooled on the opposing wall. The SIMPLE algorithm is used to handle the velocity pressure coupling. Simulation results allow determining the optimal configuration of the used porous substrate and plain fluid position in the cavity in order to optimize the performance of such solar adsorption cooling installation.

Effects of a Nonabsorbable Gas on Interfacial Heat and Mass Transfer for the Entrance Region of a Falling Film Absorber

1996 ◽  
Vol 118 (1) ◽  
pp. 45-49 ◽  
Author(s):  
T. A. Ameel ◽  
H. M. Habib ◽  
B. D. Wood
Keyword(s):  
Mass Transfer ◽  
Water Vapor ◽  
Analytical Solution ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Vertical Wall ◽  
Lithium Bromide ◽  
Entrance Region ◽  
Falling Film ◽  
Aqueous Lithium Bromide

An analytical solution is presented for the effect of air (nonabsorbable gas) on the heat and mass transfer rates during the absorption of water vapor (absorbate) by a falling laminar film of aqueous lithium bromide (absorbent), an important process in a proposed open-cycle solar absorption cooling system. The analysis was restricted to the entrance region where an analytical solution is possible. The model consists of a falling film of aqueous lithium bromide flowing down a vertical wall which is kept at uniform temperature. The liquid film is in contact with a gas consisting of a mixture of water vapor and air. The gas phase is moving under the influence of the drag from the falling liquid film. The governing equations are written with a set of interfacial and boundary conditions and solved analytically for the two phases. Heat and mass transfer results are presented for a range of uniform inlet air concentrations. It was found that the concentration of the nonabsorbable gas increases sharply at the liquid gas interface. The absorption of the absorbate in the entrance region showed a continuous reduction with an increase in the amount of air.

Unsteady flow of three-dimensional Maxwell nanofluid with variables properties over a stretching surface

2021 ◽  
pp. 095440892110390
Author(s):  
Muhammad N Khan ◽  
Shafiq Ahmad ◽  
Sohail Nadeem ◽  
El-Sayed M. Sherif ◽  
Hijaz Ahmad ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Variable Viscosity ◽  
Fluid Velocity ◽  
Mass Transfer Rate ◽  
Three Dimensional ◽  
Maxwell Fluid ◽  
Convective Boundary Condition ◽  
Convective Boundary ◽  
Viscosity Parameter

The present article focuses on the time-dependent three-dimensional Maxwell fluid flow with temperature-dependent fluid properties along the stretching sheet. The heat and mass transfer analysis are presented in the occurrence of activation energy, convective boundary condition, and non-uniform heat source/sink effect. The flow model is converted into a system of coupled ODEs with the help of a similarity transformation. The numerical built-in technique Bvp4c is employed to solve the obtained coupled ODEs. The graphical outcomes are obtained against the various parameters and discussed. It is seen from the graphs that fluid velocity diminishes for stronger values of relaxation parameter and shows an opposite trend for the variable viscosity parameter. Moreover, it is noted from the tabulated data that the heat and mass transfer rate reduces for the stronger values of unsteadiness and the variable viscosity parameter.

Simultaneous heat and mass transfer during evaporation from a film of liquid into the turbulent gas

1982 ◽  
Vol 47 (3) ◽  
pp. 766-775 ◽  
Author(s):  
Václav Kolář ◽  
Jan Červenka
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Driving Forces ◽  
Proper Definition ◽  
Definition Of ◽  
Simultaneous Heat ◽  
Theory And Experiment

The paper presents results obtained by processing a series of published experimental data on heat and mass transfer during evaporation of pure liquids from the free board of a liquid film into the turbulent gas phone. The data has been processed on the basis of the earlier theory of mechanism of heat and mass transfer. In spite of the fact that this process exhibits a strong Stefan's flow, the results indicate that with a proper definition of the driving forces the agreement between theory and experiment is very good.

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