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...

Measurements of space and time resolved subcooled pool boiling of FC-72 in low, earth, and high gravity environments were made using a microscale heater array. Data from each heater in the array were synchronized with highspeed digital video. The boiling behavior was dominated by the formation of a large primary bubble on the surface which acted as a ‘‘sink’’ for many smaller bubbles surroundin...

Passive methods to increase the heat flux on subcooled flow boiling are extremely needed modern cooling systems. Many methods, including treated surfaces and extended surfaces, have been investigated. Experimental research enhance using high sintered fiber attached surface was conducted. One bare (0 mm) four porous thickness (0.2, 0.5, 1.0, 2.0 were compared under three different mass fluxes (2...

A mode based on an additive mechanism of heat transfer is proposed for forced convection subcooled boiling of binary mixtures. The contributing modes of heat transfer are: (i) the heat transferred as latent heat by the rising bubbles, (ii) the heat transferred as the heat contained in the superheated thermal layer that is removed from the surface in the wake of the rising bubbles and (iii) the ...

Bubble lift-off diameter is characterized as the size of a bubble rising from wall, which vital in boundary condition heat transfer model and interfacial area transport equation. In this paper, mechanistic force analysis was conducted to explore predictive for vertical channel subcooled boiling flow. Specifically, component growth normal wall shear lift lead on surface. Through analysis, we fou...

This paper explores the subcooled nucleate boiling and critical heat flux (CHF) characteristics of a hybrid cooling module that combines the cooling attributes of micro-channel flow and jet impingement. A test module was constructed and tested using HFE-7100 as working fluid. Increasing the coolant’s flow rate and/or subcooling shifted both the onset of boiling (ONB) and CHF to higher heat flux...

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...