On the mechanism of the boiling process on submerged surfaces with capillary-porous covering

A simplified mathematical model is constructed which relies on physical representations of the most essential aspects of the process. An analysis of results of investigations on boiling in porous coatings yields the following information about the mechanism of the process. A vapor is formed during heating of the fluid within the porous layer, and is eliminated through certain pores while new portions of fluid are sucked in through other pores because of capillary forces. The question arises as to namely what affords the possibility of obtaining high heat fluxes as well as the process of developed nucleate boiling at such low Delta T (sometimes a fraction of a degree) while boiling on surfaces without a porous coating requires much greater heat for the formation and growth of vapor bubble nuclei. This fact can be explained by assuming that there are cavities with phase separation boundaries within the porous layer.