An experimental study is conducted to determine the nucleate pool boiling heat transfer performance of a copper-graphite (Cu-Gr) composite surface in Freon 113. The composite medium consists of ultra-high thermal conductivity graphite fibers of 0.0008~.010 mm diameter being consolidated in a copper matrix (50% area fraction). It has high thermal conductivity along the fiber directions, several ...

Experiments on the flow boiling heat transfer of almost pure CO2 and CO2-oil mixtures in horizontal smooth and micro-fin tubes have been carried out. The smooth tube is a stainless steel tube with an inside diameter of 3mm, and the micro-fin tube is a copper tube with a mean inside diameter of 3.04mm. Experiments were carried out at mass velocities from 190 to 1300kg/(ms), saturation temperatur...

Nucleation, growth and detachment of steam bubbles during nucleate boiling of a water pool at atmospheric pressure is experimentally investigated using a combination of synchronized high-speed video (HSV), infrared (IR) thermography and particle image velocimetry (PIV). The heater is a thin (<1 m), horizontal (20×10 mm 2 ), resistively-heated, indium-tin-oxide (ITO) film, vacuum-deposited on a...

This paper is the second of a two-part study concerning two-phase flow and heat transfer characteristics of R134a in a micro-channel heat sink incorporated as an evaporator in a refrigeration cycle. Boiling heat transfer coefficients were measured by controlling heat flux (q00 = 15.9 93.8W/cm) and vapor quality (xe = 0.26 0.87) over a broad range of mass velocity. While prior studies point to e...

Chilldown or quenching is a complicated process that initiates the cryogenic fluid line transport, and it involves unsteady two-phase heat and mass transfer. To advance our understanding of this process, we have reviewed recent experimental investigations. The chilldown process can be generally divided into three regimes: film boiling, transition boiling and nucleate boiling, and each regime is...