scholarly journals Numerical study of heat and mass transfer during evaporation of a turbulent binary liquid film

2015 ◽  
Vol 19 (5) ◽  
pp. 1529-1540
Author(s):  
Larbi Khalal ◽  
M’barek Feddaoui ◽  
Touria Mediouni
Keyword(s):  
Mass Transfer ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Numerical Study ◽  
Computational Study ◽  
Vertical Tube ◽  
Uniform Heat Flux ◽  
Volatile Components ◽  
Binary Liquid ◽  
Study Results

This paper deals with a computational study for analysing heat and mass exchanges in the evaporation of a turbulent binary liquid film (water-ethanol and water-methanol) along a vertical tube. The film is in co-current with the dry air and the tube wall is subjected to a uniform heat flux. The effect of gas-liquid phase coupling, variable thermophysical properties and film vaporization are considered in the analysis. The numerical method applied solves the coupled governing equations together with the boundary and interfacial conditions. The algebraic systems of equations obtained are solved using the Thomas algorithm. The results concern the effects of the inlet liquid Reynolds number and inlet film composition on the intensity of heat and mass transfer. In this study, results obtained show that heat transferred through the latent mode is more pronounced when the concentration of volatile components is higher in the liquid mixture .The comparisons of wall temperature and accumulated mass evaporation rate with the literature results are in good agreement.

scholarly journals Computational Study of Liquid Film Evaporation along a Wavy Wall of a Vertical Channel

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Monssif Najim ◽  
M’barek Feddaoui ◽  
Abderrahman Nait Alla ◽  
Adil Charef
Keyword(s):  
Mass Transfer ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Numerical Study ◽  
Computational Study ◽  
Vertical Channel ◽  
Wavy Wall ◽  
Gas Phases ◽  
Multiple Parameters ◽  
Film Evaporation

A numerical study of mixed convection heat and mass transfer along a vertical channel with a wavy wall is performed. The wavy wall is heated by a constant flux, while the other is adiabatic. The discretisation of equations in both liquid and gas phases is realised using an implicit finite difference scheme. Results of simulation compare the effect of multiple parameters, especially amplitude and characteristic length of the curve, on the liquid film evaporation process. The results indicate that heat and mass transfer is enhanced by increasing the amplitude and number of wall waves. Moreover, a very small value of waves amplitude of the wall may reduce the sensible heat and mass transfer.

scholarly journals Heat and mass transfer modeling during laminar condensation of non-cryogenic downward fluids flow in a small vertical tube

2020 ◽  
Vol 7 (4) ◽  
pp. 1-19
Author(s):  
Y. Belkassmi ◽  
L. Elmaimouni ◽  
A. Rafiki ◽  
K. Gueraoui ◽  
N. Hassanain
Keyword(s):  
Mass Transfer ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Vertical Tube ◽  
Film Condensation ◽  
Two Phase ◽  
Cryogenic Fluids ◽  
Mass Transfer Mechanism ◽  
Mass Transfer Modeling ◽  
Good Agreement

The purpose of this paper is to investigate mass and heat transfer in the process of film condensation of vapor-air mixture for non-cryogenic fluids flow in a small vertical tube. A two-phase mathematical model is developed to model the mixture and liquid film. The governing equations for mixture and liquid-film have been resolved using a numerical method. Furthermore, this phenomenon analyzed is linked to a steady-state. Therefore, the development of numerical codes allows us to investigate the effect of implicated parameters on this phenomenon. Ethanol and methanol as non-cryogenic typical working fluids are realized for a good understanding of the heat and mass transfer mechanism during condensation. In this way, several effects of influencing parameters were examined. The predicted results showed a good agreement with experimental data.

scholarly journals Evaporation and condensation of falling binary liquid film

2017 ◽  
Vol 21 (1 Part A) ◽  
pp. 211-222
Author(s):  
Abdelaziz Nasr ◽  
Abdulmajeed Al-Ghamdi
Keyword(s):  
Mass Transfer ◽  
Ethylene Glycol ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Volatile Component ◽  
Water Evaporation ◽  
Gas Temperature ◽  
Evaporation And Condensation ◽  
Binary Liquid ◽  
Vapour Concentration

This paper investigates a numerical analysis of coupled heat and mass transfer during the simultaneous evaporation and condensation in the presence of a binary liquid film flowing on one of two parallel vertical plates under mixed convection. The first plate of a vertical channel is externally insulated and wetted by a binary liquid film while the second one is dry and isothermal. The liquid mixture consists of water (the more volatile component) and ethylene glycol while the gas mixture has three components: dry air, water vapour and ethylene glycol vapour. The conducted simulations enable the analysis of the heat and mass transfer during water evaporation and ethylene glycol condensation for different inlet gas properties. It is found that an increase of the inlet vapour concentration of ethylene glycol enhances the water evaporation while the increase of the inlet vapour concentration of water slightly enhances the ethylene glycol vapour condensation. The increase of inlet gas temperature considerably benefits the water evaporation and slightly influences the ethylene glycol condensation.

scholarly journals Numerical study of heat and mass transfer during evaporation of a thin liquid film

2015 ◽  
Vol 19 (5) ◽  
pp. 1805-1819 ◽  
Author(s):  
M’hand Oubella ◽  
M’barek Feddaoui ◽  
Rachid Mir
Keyword(s):  
Mass Transfer ◽  
Liquid Film ◽  
Heat And Mass Transfer ◽  
Numerical Study ◽  
Thin Liquid Film ◽  
Simple Algorithm ◽  
Liquid Films ◽  
Inlet Temperature ◽  
Transfer Rates ◽  
Film Evaporation

A numerical study of mixed convection heat and mass transfer with film evaporation in a vertical channel is developed. The emphasis is focused on the effects of vaporization of three different liquid films having widely different properties, along the isothermal and wetted walls on the heat and mass transfer rates in the channel. The induced laminar downward flow is a mixture of blowing dry air and vapour of water, methanol or acetone, assumed as ideal gases. A two-dimensional steady state and elliptical flow model, connected with variable thermo-physical properties, is used and the phase change problem is based on thin liquid film assumptions. The governing equations of the model are solved by a finite volume method and the velocity-pressure fields are linked by SIMPLE algorithm. The numerical results, including the velocity, temperature and concentration profiles, as well as axial variations of Nusselt numbers, Sherwood number and dimensionless film evaporation rate are presented for two values of inlet temperature and Reynolds number. It was found that lower the inlet temperature and Re, the higher the induced flows cooling with respect of most volatile film. The better mass transfer rates related with film evaporation are found for a system with low mass diffusion coefficient.

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