A More Accurate Prediction of Liquid Evaporation Flux

Document Type: Research Article

Authors

1 Department of Chemistry, University of Isfahan, P.O. Box 81746-73441, Isfahan, I. R. IRAN

2 Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, I. R. IRAN

Abstract

In this work, a more accurate prediction of liquid evaporation flux has been achieved. The statistical rate theory approach, which is recently introduced by Ward and Fang and exact estimation of vapor pressure in the layer adjacent to the liquid–vapor interface have  been used for prediction of this flux. Firstly, the existence of an equilibrium layer adjacent to the liquid-vapor interface is considered and the vapor pressure in this layer and its thickness calculated. Subsequently, by using the Fick’s second law, an appropriate vapor pressure expression for the pressure of equilibrium layer is derived and by this expression and the statistical rate theory approach, evaporation flux is predicted more accurately than the previous work. Finally, some novel steady state evaporations are simulated and the effects of both liquid and vapor temperature and the effect of the length of the evaporation chamber on the evaporation flux are investigated.

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[1] Knudsen, M., Molecular resistance encountered by a plate moving in gas, Ann. Phys. Leipzig, 47, 641 (1915).
[2] Shankar, P.N., A kinetic  theory of  steady condensation, J. Fluids Mech., 40, 385 (1970).
[3] Pao, Y.P., Temperature and density jumps in the kinetic theory of gases and vapors, Phys. of Fluids, 14, 1340 (1971).
[4] Sone, Y., Onishi,  Y.,  Kinetic  theory  of  evaporation and condensation, J. Phys. Soc. Japan, 44, 1981 (1978).
[5] Gajewski, P., Kulicki, A., Wisneiski, A., Zgorzelski, M., Kinetic theory approach to the vapor-phase phenomena in a nonequilibrium condensation process, Phys. of Fluids, 17, 321 (1974).
[6] Siewert, C.E., Thomas Jr, J.R., Half-space problems in the kinetic theory of gases, Phys. of Fluids, 16, 1557 (1973).
[7] Cipolia Jr., J.W., Lang, H., Loyolka, S.K., Kinetic theory of condensation and evaporation, J. Chem. Phys., 61, 69 (1974).
[8] Arkeryd, L., Nouri, A., A condensation-evaporation problem in kinetic theory, SIAM J. Math. Anal., 29, 30 (1998).
[9] Ward, C.A., Fang, G., Expression for predicting liquid evaporation flux: statistical rate theory approach, Phys. Rev. E, 59, 429 (1999).
[10] Ward, C.A., Fang, G., Temperature measured close to the interface of an evaporating liquid, Phys. Rev. E, 59, 417 (1999).
[11] Tung, L.N., Drickaner, H.G., Diffusion through an interface – binary system, J. Chem. Phys., 20, 6 (1952).
[12] Bird, R.B., Stewart, W.E., Lightfoot, E.N., “Transport Phenomena”, Wiley, New York (1966).
[13] Hirschfelder, J.O., Curtiss, C.F., Bird, R.B., “The Molecular Theory of Gases and Liquids”, Wiley, New York, (1954).