Boiling on Coated Surfaces and in Porous Structures

The objective of this article is to suggest and discuss physical models and theoretical fundamentals of heat and mass transfer phenomena when boiling on coated surface with respect to test data of such porous covering technologies as metal-fibrous, plasma sprayed, sintered-powdered, and screen wicks. Theoretical study of mathematical models of boiling on coated surfaces is performed to obtain the accepted correction within the scope of the known experimental data. The findings indicate a significant influence on the heat and mass transfer phenomena at the wall-porous coating zone, and the presence of different kinds of liquid-vapor structures inside the porous coating. Numerical modeling and experimental analyses demonstrate the existence of the common law of "local" heat and mass transfer when boiling on coated surfaces and in porous structures. Considering this law as the "first-level" model one can suggest the basic theory of heat and mass transfer when boiling on coated surfaces. In addition, the suggested approach uses the irreversibility minimization principle to the "second- and third-level" models. The postulated theory is in agreement with the known experimental data.