Perturbation Techniques In Conduction Controlled Freeze Thaw Heat Transfer

Author : Virgil J. Lunardini
Publisher :
ISBN 13 :
Total Pages : 340 pages
Book Rating : 4.:/5 (227 download)

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Download or read book Heat Conduction with Freezing Or Thawing written by Virgil J. Lunardini and published by . This book was released on 1986 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Freezing of water or melting of ice are phenomena that underlie many important scientific and engineering studies of cold regions. Mathematical methods of treating these phase-change heat transfer problems are critical to understanding and dealing with the problems that freeze-thaw causes. While convection may be an important heat transfer mode, it can often be neglected without significant error. This report deals only with problems for which conduction is the basic heat transfer mode or for which the solutions can be obtained in terms of conduction-like problems. Where possible, exact solutions are presented, but since these are quite limited for phase-change problems, approximate solutions are examined in some detail. The approximate methods are 1) the perturbation method, which leads to quasi-stationary techniques, 2) the heat balance integral method, and 3) Biot's variational principle. THe theory associated with these methods is discussed in the appendixes. THe available exact solutions are derived and explained. Graphical solutions are used to generate design curves-such as those for phase-change depth, temperature, and heat flow vs time. The results are presented so as to be easily accessible to practicing engineers without recourse to elaborate calculations. This is especially true for application to soil systems. Keywords: Conduction, Freezing, Heat transfer, Melting, Phase change, Thawing. (mjm).