High-speed video and infrared thermometry were used to obtain timeand space-resolved information on bubble nucleation and heat transfer in pool boiling of water. The bubble departure diameter and frequency, growth and wait times, and nucleation site density were directly measured for a thin, electrically-heated, indium-tin-oxide surface, laid on a sapphire substrate. These data are very valuabl...

Pool boiling is of interest in high heat flux applications because of its potential for removing large amount of heat resulting from the latent heat of evaporation and little pressure drop penalty for circulating coolant through the system. However, the heat transfer performance of pool boiling systems is not adequate to match the cooling ability provided by enhanced microchannels operating und...

A problem of current interest in geothermal energy extraction is the injection of cold water into a porous medium containing superheated vapor. Such injection will cause a boiling front to move away from the injection point. When flow is approximated as being one-dimensional radial, it can be shown from similarity variable concepts that temperature, pressure, and boiling rate at the front are c...

Critical Heat Flux, or CHF, is an important condition that defines the upper limit of safe operation of heat transfer equipment employing boiling heat transfer in heat flux controlled systems. Although significant research has been conducted in this field, a clear understanding of the basic mechanisms leading to the CHF condition is still lacking. The present article covers the subcooled flow b...

Theoretical and experimental study of transient heat transfer parameters related to downward flowing water in a circular concentric annular channel is conducted. The cooling channel is exposed internally to sinusoidal heat flux and has an adiabatic outer surface. The present theoretical study investigated the heat transfer and thermodynamic parameters during of 25%, 50%, and 75% flow reduction ...

Phase change of pore fluid (boiling/condensing) in rock cores under conditions representative of geothermal reservoirs results in alterations of the electrical resistivity of the samples. In fractured samples, phase change can result in resistivity changes that are more than an order of magnitude greater than those measured in intact samples. These results suggest that electrical resistivity mo...

The paper reports pressure drop data for hydrocarbon fluids boiling in vertical upflow in a 8.68 m long, 25.4 mm i.d. tube, heated by direct electrical heating. These data were recorded simultaneously with the boiling heat transfer measurements. The systematic trends of the measured pressure gradient with respect to vapour quality, mass flux and pressure are examined. This provides useful infor...

Experiments were performed to study subcooled film boiling of performance liquid PF5060 (made by 3-M Company) on a horizontal copper disc. The experiments were performed for two regimes of film boiling involving departing vapor bubbles (low subcooling) and nondeparting vapor bubbles (high subcooling). By employing high speed digital camera, data were obtained for temporal variation of bubble he...

Calculation of excess quantities of ethylene glycol + water binary fluid systems at seven absolute temperatures (293.15 to 353.15) K from experimentally determined values of density and shear viscosity were presented in previous work. The examination of related functions beside the quality of correlation from several equations on these experimental values has also been reported. Considering...