A new passive solar water pasteurization system based on density difference flow principles has been designed, built and tested. The system contains no valves and regulates flow based on the density difference between two columns of water. The new system eliminates boiling problems encountered in previous designs. Boiling is undesirable because it may contaminate treated water. The system with ...

This study is the first attempt at extending the Interfacial Lift-off CHF Model to subcooled flow boiling conditions. A new CHF database was generated for FC-72 from ground tests as well as from microgravity tests that were performed in parabolic flight trajectory. These tests also included high-speed video imaging and analysis of the liquid–vapor interface during the CHF transient. Both the CH...

0017-9310/$ see front matter 2009 Elsevier Ltd. A doi:10.1016/j.ijheatmasstransfer.2009.09.035 * Corresponding author. Tel.: +1 860 654 9325; fax E-mail address: [email protected] (G. Qui An experimental study was conducted to investigate how the addition of small amounts of a surfactant influences the heat transfer characteristics in a thin boiling liquid film flowing in a diverging ope...

Flow boiling in microchannels and minichannels has received considerable attention in the past decade. The interest stems from the possibility of achieving the extremely high heat fluxes, over 1 kW/cm, needed for future generation electronics cooling application. The attention has been focused on obtaining experimental heat transfer and pressure drop data, but the fundamental aspects of nucleat...

This study uses high-speed imaging to characterize microchannel slug flow boiling using a novel experimental test facility that generates an archetypal flow regime suitable for highfidelity characterization of key hydrodynamic and heat transfer parameters. Vapor and liquid phases of the fluorinated dielectric fluid HFE-7100 are independently injected into a T-junction to create a saturated two-...

The interfacial instabilities important to the modeling of critical heat flux (CHF) in reduced-gravity systems are sensitive to even minute body forces, especially for small coolant velocities. Understanding these effects is of paramount importance to both the reliability and safety of two-phase thermal management loops proposed for future space and planetary-based thermal systems. Unfortunatel...

This paper is the first of a two-part study concerning measurement and prediction of saturated flow boiling heat transfer in a water-cooled micro-channel heat sink. In this paper, new experimental results are discussed which provide new physical insight into the unique nature of flow boiling in narrow rectangular micro-channels. The micro-channel heat sink contained 21 parallel channels having ...

Local heat transfer coefficients and pressure drops during boiling of the dielectric liquid fluorinert FC-77 in parallel microchannels were experimentally investigated in recent work by the authors. Detailed visualizations of the corresponding two-phase flow regimes were performed as a function of a wide range of operational and geometric parameters. A new transition criterion was developed for...