Abstract

The optimum condition for the sublimation process taking place in a porous half space are determined in this paper. The vapor mass concentration at the surface of the porous medium and the initial frozen mass concentration in the frozen region are predetermined. The optimum condition is found by determining the vapor mass concentration at the sublimation front between the vapor and frozen phases, that yields the maximum flux of the vapor mass at the sublimation front. Exact solutions of the temperature and vapor mass concentration as well as the location of the moving sublimation front are obtained. The surface temperature used as the thermal controller is also determined to match the optimum sublimation condition.

Issue Section:
Porous Media
Keywords:
Heat Transfer, Moving Boundaries, Phase Change, Porous Media, porous materials, mass transfer, heat transfer, sublimation, temperature
Topics:
Porous materials, Temperature, Vapors, Heat transfer
1.
Cho
,
S. H.
,
1975
, “
An Exact Solution of the Coupled Phase Change Problem in a Porous Medium
,”
Int. J. Heat Mass Transf.
,
18
, pp.
1139
–
1142
.
2.
Mikhailov
,
M. D.
,
1975
, “
Exact Solution of Temperature and Moisture Distributions in a Porous Half-Space With Moving Separation Front
,”
Int. J. Heat Mass Transf.
,
18
, pp.
797
–
804
.
3.
Mikhailov
,
M. D.
,
1976
, “
Exact Solution for Freezing of Humid Porous Half-Space
,”
Int. J. Heat Mass Transf.
,
19
, pp.
651
–
655
.
4.
Lin
,
S.
,
1981
, “
An Exact Solution of the Sublimation Problem in a Porous Medium
,”
ASME J. Heat Transfer
,
103
, pp.
165
–
168
.
5.
Lin
,
S.
,
1982
, “
An Exact Solution of the Sublimation Problem in a Porous Medium, Part II—With an Unknown Temperature and Vapor Concentration at the Moving Sublimation Front
,”
ASME J. Heat Transfer
,
104
, pp.
808
–
811
.
6.
Lin
,
S.
,
1982
, “
An Exact Solution of the Desublimation Problem in a Porous Medium
,”
Int. J. Heat Mass Transf.
,
25
, pp.
625
–
630
.
7.
Slattery, J. C., 1972, Momentum, Energy and Mass Transfer in Continua, McGraw-Hill, New York, Sections 7.3 and 10.3.
8.
Carslaw, H. S., and Jager, J. C., 1959, Conduction of Heat in Solids, Oxford University Press, London, Chap. XI.
9.
Cengel, Y. A., and Boles, M. A., 1994, Thermodynamics—An Engineering Approach, McGraw-Hill, New York, Section 11.3.
Copyright © 2002
 by ASME
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