Subcooled flow boiling was experimentally investigated in a horizontal annulus with temperature-controlled surface and transparent outer pipe facilitating visualization. Boiling occurs on copper tube diameter of 12 mm an 2 gap. Refrigerant R245fa is used as working fluid. The focus this study to explore the effect heat flux variation patterns at approximately constant inlet conditions fluid (fi...

0142-727X/$ see front matter 2008 Elsevier Inc. A doi:10.1016/j.ijheatfluidflow.2008.08.003 * Corresponding author. Tel.: +1 979 845 4500; fax E-mail address: [email protected] (D. Banerjee Surface temperature fluctuations that occur locally underneath departing bubbles in pool boiling are shown to result in local heat transfer coefficients ranging from 1 to 10 kW/cm. These estimates were repo...

Flow boiling in microchannels has received considerable attention from researchers worldwide in the last decade. A scaling analysis is presented to identify the relative effects of different forces on the boiling process at microscale. Based on this scaling analysis, the flow pattern transitions and stability for flow boiling of water and FC-77 are evaluated. From the insight gained through the...

Flow boiling of the perfluorinated dielectric fluid FC-77 in a silicon microchannel heat sink is investigated. The heat sink contains 60 parallel microchannels each of 100 m width and 389 m depth. Twenty-five evenly distributed temperature sensors in the substrate yield local heat transfer coefficients. The pressure drop across the channels is also measured. Experiments are conducted at five ...

Surface enhancement is a potential way to improve the performance of flow boiling in microchannels, which is considered to be one of the most promising cooling methods to solve thermal management challenges faced by future semiconductor products. Considerable research has been done on examining the functions of engineered surfaces. However, the mechanism of how these surfaces improve the flow b...

Mineral scaling constitutes a major problem in geothermal fields. It imposes adverse impacts on the performance of power plant as mineral precipitates and clogs facilities, affecting steam production. This paper identifies processes leading to formation calcite, pyrite, anhydrite scales Well-1 located at Matalibong sector, one production sectors Tiwi Geothermal Field, Albay, Philippines, using ...

A new cooling scheme is proposed where the primary working fluid flowing through a micro-channel heat sink is pre-cooled to low temperature using an indirect refrigeration cooling system. Cooling performance was explored using HFE 7100 as working fluid and four different micro-channel sizes. High-speed video imaging was employed to help explain the complex interrelated influences of hydraulic d...

In a boiling liquid expanding vapor explosion (BLEVE), the superheating and boiling of the liquefied gas inside the vessel as it fails is important information necessary to understand the mechanism of this type of disaster. In this paper, a small-scale experiment was developed to investigate the possible processes that could lead to a BLEVE. Water was used as the test fluid. High-speed video wa...

In this study, direct numerical simulation for the bubble condensation in the subcooled boiling flow was performed. The main goal was to develop the CFD modeling for the bubble condensation and to evaluate the accuracy of the VOF model with the developed CFD modeling. CFD modeling for the bubble condensation was developed by modeling the source terms in the governing equations of VOF model usin...