Immersion Cooling of a Simulated Electronic Chip Protruding into a Flow Channel

Abstract

Nucleate boiling and critical heat e ux from the top and side surfaces of a simulated electronic chip protruding into a rectangular channel has been studied. To ascertain the contributions of heat transfer from the sides and top of the simulated electronic chip, boiling from the sides was virtually eliminated by the use of a thin (0.025 mm) foil heater on top of a block of insulating material. It was found that single-phase heat transfer and critical heat e ux are markedly greater for a surface protrusion height of 0.71 mm as compared to a e ush surface. This increase was seen for e ow velocities greater than 1 m/s and a subcooling of 20 8C. The results are compared to that for a copper block heated from below under similar e uid and geometry constraints. These comparisons show that the vapor emanating from the upstream side of the copper block plays an important role in either decreasing or increasing the critical heat e ux. Additional results were obtained for the copper block where heat transfer from the upstream side was obstructed. These results indicate that under some conditions of subcooling and e ow rate an optimal amount of upstream side vapor production exists.