This second part of a two-part study examines the prediction of saturated flow boiling heat transfer in mini/micro-channels. The first part culminated in a technique for determining the dryout incipience quality corresponding to substantial deterioration in the heat transfer coefficient. In this part, a consolidated database for flow boiling in mini/micro-channels is amassed from 31 sources, of...

Measurements of film mass flow rate for annular, diabatic steam-water flow in tubes are presented. The measurements were carried out with four axial power distributions and at several axial positions at conditions typical for boiling water reactors, i.e. 7 MPa pressure and total mass flux in a range from 750 to 1750 kg/ms. The results show that the influence of the axial power distribution on t...

This work concerns dryout experiments in which a tube, initially containing water, filled up or partially filled and at 1,2 or 3 atmosphere pressures, is heated. The initial water column experience three thermal regions. The first region, called the first period, involves heating of the tube until saturation conditions are obtained in the water. Boiling of the water in the tube causes swelling ...

Heat pipes and vapor chambers are passive thermal management devices used for efficient heat transport by phase change. Their operation is enabled capillary pumping of the working fluid in a porous wick, which operationally limited maximum pressure head it can provide. This limit marks input at generated overcome drop wick; operating above steady state leads to dryout. increasingly being electr...

This two-part study concerns the development of a generalized approach to predicting both Nucleate Boiling dominated and Convective Boiling dominated heat transfer in mini/micro-channel flows. Both heat transfer regimes exhibit substantial reduction in the heat transfer coefficient at the location of partial annular liquid film dryout, hence the need to ascertain the occurrence of this importan...

Supercritical heat transfer systems may undergo trans-critical procedures and work at subcritical conditions during startup, shutdown, or some accidents. However, well-validated models for the high-pressure condition ( P/Pc<mml...

Experiments were conducted to determine the influence of local vapor quality on local heat transfer coefficient in flow boiling in an array of microchannels. Additionally, the variation of local heat transfer coefficient along the length and width of the microchannel heat sink for given operating conditions was investigated over a range of flow parameters. Each test piece includes a silicon par...