THE INTERLINE HEAT-TRANSFER OF EVAPORATING THIN-FILMS ALONG A MICRO GROOVED SURFACE

An analytical investigation of the hear transfer characteristics for e vaporating thin liquid films in V-shaped microgrooves with nonuniform input heat flux was conducted This investigation assumed that the capi llary pressure difference caused by the receding of the meniscus is re sponsible for the axial liquid flow along the groove, and that the dis joining pressure difference along the groove side wall provided the dr iving force for the flow up the groove wall. The combined heat transfe r mechanisms of both liquid conduction and interfacial vaporization we re used to describe the local interfacial mass flux in the interline r egion. Based on this approach, a local hear transfer coefficient was d efined The local and average heat transfer coefficients were both foun d to be sensitive to the characteristic thermal resistance ratio. In a ddition, when the film superheat was constant, the primary factor affe cting the length of the evaporating interline region was found to be t he heat flux supplied to the bottom plate, and for high heat flux cond itions, the highest heat transfer coefficient did not necessarily exis t at the axial dryout point. The expression developed for the evaporat ing film profile was shown to assume an exponential form if the heat f lux distributed on the active interline region was assumed to be unifo rm.