Modelling Of Dropwise Evaporative Cooling On A Semi-infinite Solid Subjected To Radiant Heat Input

Abstract

A model for the prediction of dropwise evaporative cooling over hot solid surfaces is proposed for the case of radiant heat input. A detailed representation of the droplet shape during the transient is provided. The direct radiant contribution to the evaporative process is expressed as a liquid-vapor interfacial term and a constant heat absorption term within the liquid layer. The liquid layer is treated with a onedimensional heat conduction approximation justified by previous results and three submodels are used to describe it during the transient. A boundary element method for the solid thermal behavior, previously developed, is extended to this case. The results obtained from a closed-form solution, with simplified solid-liquid interfacial boundary conditions, are also included. Comparisons with the experimental data illustrate the adequacy of the model and the performance of the closed-form solution.

Fire suppression studies

“…In the case of wood [27], this factor has been shown to have much smaller ef fect. More ac cu rate mod el ing of sur face cool ing due to drop let im pact may be de veloped along the lines pro vided in stud ies [29][30][31]. A re cent study [32] has pro vided very care ful and valu able com pu ta tions of heat trans fer be tween drop lets and hot sur face, taking into ac count the ef fect of drop let bounc ing.…”

Modelling Aspects of Sprinkler Spray Dynamics in Fires

“…The temperature gradient at the surface, shown inside the integrals, is given by the solution of the thermal transient in the liquid subjected to a liquid-vapour boundary condition that encompasses water vapour mass transfer as well as the convective heat transfer component (White et al, 1994). This boundary condition can be expressed as:…”