Liquid Immersion Cooling of a Longitudinal Array of Discrete Heat Sources in Protruding Substrates: II—Forced Convection Boiling

Forced convection boiling experiments have been performed for an in-line 1 x 10 array of discrete heat sources, flush mounted to protruding substrates located on the bottom wall of a horizontal flow channel. FC-72, a dielectric fluorocarbon liquid, was used as the heat transfer fluid, and the experiments covered a range of flow velocities, degrees of fluid subcooling, and channel heights. The maximum heater-to-heater surface temperature variation was less than 2.5°C and was insensitive to channel height under conditions of fully developed nucleate boiling. Although the fluid velocity influenced the heat flux for partially developed nucleate boiling, its influence was muted for fully developed nucleate boiling. The heat flux associated with a departure from nucleate boiling increased with increasing velocity, subcooling, and channel height; however, the effect of channel height was only significant when all of the upstream heaters were energized.