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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Boiling and heat transfer in porous media: Fundamental aspects and applications

Get access (open in a dialog) DOI: 10.1615/IHTC12.3180
11 pages

摘要

Boiling in porous media (BPM) involves numerous mechanisms. This is due to the existence of three phases solid - liquid and vapor. All these phases interact with each other and make the phenomena highly coupled. In this paper an overview of the basic phenomena and applications where BPM plays an important role are presented. Vapor nucleation and two-phase flow exhibit a typical behavior according to the porous medium structure. For viscous two-phase flows the saturation temperature remains constant while it changes when the inertial effects are dominant. Nonstationary effects may appear in some situations. In this case thermal and hydraulic fluctuations are observed. The present analysis shows that the main phenomena are well identified. Nevertheless the detailed description is still in progress. Theoretical models based on continuous approaches are being developed and solved numerically. These approaches allow the heat and mass transfer variables to be predicted. However the results remain qualitative because of the closure relations. These relations are determined by heuristic approaches, so they are only applicable for limited cases. For applications, several situations exist where BPM must be understood in order to avoid malfunctions, to improve the quality of the products, or to enhance the heat transfer.