A brief review of recent low gravity boiling research by investigators based in the United States is performed. Topics covered include bubble dynamics, nucleate pool boiling and CHF, transition boiling, boiling of mixtures, electric ˆeld eŠects, acoustic ˆeld eŠects, and ‰ow boiling. Planned research activities and recommendations for future

Nanofluids are engineered colloidal suspensions of nanoparticles in water, and exhibit a very significant enhancement (up to 200%) of the boiling Critical Heat Flux (CHF) at modest nanoparticle concentrations (50.1% by volume). Since CHF is the upper limit of nucleate boiling, such enhancement offers the potential for major performance improvement in many practical applications that use nucleat...

The onset of nucleate boiling in the flow of water through a microchannel heat sink was investigated. The microchannels considered were 275 lm wide by 636 lm deep. Onset of nucleate boiling was identified with a high-speed imaging system and the heat flux at incipience was measured under various flow conditions. An analytical model was developed to predict the incipient heat flux as well as the...

Heat transfer coefficient in nucleate pool boiling near critical heat flux at least one orderhigher than the convectional heat transfer modes. In this paper, an experimental setup isdesigned and fabricated to investigate the mechanism of heat transfer from boiling surface tobulk liquid near critical heat flux. The images of pool boiling near the high heat flux regionreveals that the individual ...

The state-of-the-art for Direct Numerical Simulation (DNS) of boiling multiphase flows is reviewed, focussing on potential of available computational techniques, the level of current success for their applications to model several basic flow regimes (film, pool-nucleate and wall-nucleate boiling – FB, PNB and WNB, respectively). Then, we discuss multiphysics and multiscale nature of practical b...

This work describes an improved design for a nuclear fuel rod, which was developed using an experimental circuit that simulates the nuclear rod environment in a pressurized water reactor (PWR). The heat exchanger circuit runs atmospheric to high-pressure boiling water through an annular finned tube (153 fins), which is used to enhance confined heat transfer rates and guide the nucleate boiling ...

Nucleate pool boiling heat transfer coefficients of Al2O3-water and TiO2-water nanofluids have been experimentally measured on three horizontal tubes with different materials and similar roughness under atmospheric pressure. Results revealed that the presence of nanoparticles in the base fluid leads to an increase in pool boiling heat transfer coefficients on stainless steel and brass tubes in ...

The heat flux predictions of six different models proposed to explain the nucleate boiling phenomenon are compared with the corresponding heat flux measurements at the same levels of subcooling and acceleration. It is shown that none of these models can adequately predict nucleate boiling heat flux for other than saturated boiling conditions at standard gravity and that all of the models agree ...