THERMAL SCIENCE

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M'hand Oubella

,

M'barek Feddaoui

,

Rachid Mir

NUMERICAL STUDY OF HEAT AND MASS TRANSFER DURING EVAPORATION OF A THIN LIQUID FILM

ABSTRACT
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.
KEYWORDS
film evaporation, mixed convection, heat and mass transfer, vertical channel
PAPER SUBMITTED: 2013-01-28
PAPER REVISED: 2013-11-03
PAPER ACCEPTED: 2013-11-05
PUBLISHED ONLINE: 2013-11-16
DOI REFERENCE: https://doi.org/10.2298/TSCI130128145O
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2015, VOLUME 19, ISSUE Issue 5, PAGES [1805 - 1819]
REFERENCES
  1. Lin, T.F., Chang, C.J., Yan, W.M., Analysis of combined buoyancy effects of thermal and mass diffusion on laminar forced convection heat transfer in a vertical tube, ASME J. Heat Transf, 110 (1988), pp. 337-344
  2. Yan, W.M., Lin, T.F., Tsay, Y.L., Evaporative cooling of liquid film through interfacial heat and mass transfer in a vertical channel - I. Experimental study, Int. J. Heat Mass Transf, 34 (1991), pp. 1105-1111
  3. Yan, W.M., Lin, T.F., Evaporative cooling of liquid film through interfacial heat and mass transfer in a vertical channel - II. Numerical study, Int. J. Heat Mass Transfer, 34 (1991), pp. 1113-1124
  4. Yan, W.M., Evaporative cooling of liquid film in turbulent mixed convection channel flows. Int J Heat Mass Transf, 41 (1998), pp.3719-3729.
  5. Feddaoui, M., Belahmidi, E., Mir, A., Bendou, A., Numerical study of the evaporative cooling of liquid film in laminar mixed convection tube flows, Int. J. Therm. Sci, 40 (2001), pp. 1011-1019.
  6. Feddaoui, M., Meftah, H., Mir, A., The numerical computation of the evaporative cooling of falling water film in turbulent mixed convection inside a vertical tube, Int. Comm. Heat and Mass Transf, 33 (2006), pp. 917-927.
  7. Feddaoui, M., Mir, A., Turbulent mixed convection heat and mass exchanges in evaporating liquid film along a vertical tube. Int. J. Heat Exchangers, 8 (2007), pp. 15-31.
  8. Huang, C.C., Yan, W.M., Jang, J.H., Laminar mixed convection heat and mass transfer in vertical rectangular ducts with film evaporation and condensation, Int. J. Heat Mass Transf, 48 (2005), pp. 1772-1784
  9. Jang, J.H., Yan, W.M., Thermal protection with liquid film in turbulent mixed convection channel flows, Int. J. Heat Mass Transf, 49 (2006), pp. 3645-3654
  10. Hammou, Z.A., Benhamou, B., Galanis, N., Orfi, J., Laminar mixed convection of humid air in a vertical channel with evaporation or condensation at the wall, Int. J. Therm. Sci, 43 (2004), pp. 531-539
  11. Azizi, Y., Benhamou, B., Galanis, N., El-Ganaoui, M., Buoyancy effects on upward and downward laminar mixed convection heat and mass transfer in a vertical channel, Int. J. Numer. Methods Heat Fluid Flow, 17 (2007), pp. 333-353
  12. Kassim, M.A., Benhamou, B., Harmand, S., Effect of air humidity at the entrance on heat and mass transfers in humidifier intend for a desalination system, Applied thermal Engineering, 31 (2011), pp. 1906-1914
  13. Laaroussi, N., Lauriat, G., Desrayaud, G., Effects of variable density for film evaporation on laminar mixed convection in a vertical channel, Int. J. Heat Mass Transf, 52 (2008), pp. 151-164
  14. Perry, D., Perry's, Chemical Engineers', Handbook, Mc Graw-Hill, New York, 1999
  15. Reid, R.C., Praussita, J.M., Sherwood, T.K., The properties of gas and Liquid, Hemisphere, McGraw-Hill, New York, 1977.
  16. Patankar, S.V., Numerical Heat Transfer and Fluid Flow, Hemisphere, New York, 1980
  17. Versteeg, H.K., Malalasekera, W., An Introduction to computational Fluid Dynamics: the finite volume method, Longman Scientific & Technical, 1995.
  18. Desrayaud, G., Lauriat, G., Heat Flow reversal of laminar convection in the entry region of symmetrically heated, vertical plate channels, Int. J. Therm. Sci, 48 ( 2009), pp. 2036-2045
  19. Yan, W.M., Lin, T.F., combined heat and mass transfer in laminar forced convection channel flows, Int. Comm. Heat Mass Transf, 15 (1988), pp. 333-343.
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Numerical study of heat and mass transfer during evaporation of a thin liquid film

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