in the present paper, an analysis was carried out to investigate effects of radiation on a free convection flow bounded by a vertical surface embedded in a porous medium with constant suction velocity. it was under the influence of uniform magnetic field in the presence of a homogenous chemical reaction and viscous dissipation with constant heat and mass flux. the non-dimensional governing equa...

thin bonded films have many applications in antireflection and reflection coating, insulating and conducting films and semiconductor industries. thermal conductivity is one of the most important parameter for power packaging since the thermal resistance of the interconnections is directly related to the heat removal capability and thermal management of the power package. the defects in material...

Phase change heat transfer is fundamentally important for thermal energy conversion and management, such as in electronics with power density over 1 kW/cm^2. The critical heat flux (CHF) of phase change heat transfer, either evaporation or boiling, is limited by vapor flux from the liquid-vapor interface, known as the upper limit of heat flux. This limit could in theory be greater than 1 kW/cm2...

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...

Function approximation is the problem of nding a function that best explains the relationship between independent variables and a dependent variable. We propose a genetic hybrid for the critical heat ux function approximation which critically a ects the performance of nuclear plants. The problem is represented for genetic algorithm in a way that exploits the relationships between parameters. Th...

Pool boiling on thin, uniform porous coatings is examined experimentally using different copper particle diameters (between 40 and 80 lm), fabrications (loosely packed, shaken, or pressed), and particle characteristics (solid or porous particle) with coating thickness varying between 3 and 5 particle diameters. The results show that the critical heat flux (CHF) is about 1.8 times for all the co...

The critical heat flux (CHF) limit is an important consideration in the design of most flow boiling systems. Before the use of microchannels under saturated flow boiling conditions becomes widely accepted in cooling of high-heat-flux devices, such as electronics and laser diodes, it is essential to have a clear understanding of the CHF mechanism. This must be coupled with an extensive database ...

Nanofluids are engineered colloids composed of nano-size particles dispersed in common fluids such as water or refrigerants. Using an electrically controlled wire heater, pool boiling Critical Heat Flux (CHF) of Alumina and Silica water-based nanofluids of concentration less than or equal to 0.1 percent by volume were measured. Silica nanofluids showed CHF enhancement up to 68% and there seems ...

Paolo Di Marco Walter Grassi Dipartimento di Energetica, Universit?~ di Pisa, Pisa, Italy • The purpose of the paper is to experimentally assess the effect exerted by subcooling degree and heat-up rate (i.e., the rate of increase of thermal flux) on the phenomenon of nucleate boiling in the presence of an electric field. To this aim, an experimental facility was set up to investigate pool boili...