Experimental Testing and Numerical Modeling of Spray Cooling Under Terrestrial Gravity Conditions

Abstract

Baseline tests were performed for a spray cooling system using subcooled fluid under terrestrial gravity conditions, and a steady state numerical model of the glass heater pedestal assembly was built using ANSYS finite element software. A parametric study was performed to study the effects of volumetric flow rate, heat transfer rate, and orientation with respect to gravity on the experimental system. The numerical model data was compared with the experimental data in order to determine the spray heat transfer coefficient along the top of the heated surface. For a volumetric flow range gal/hr and a heat load range of W, the estimated spray heat transfer coefficient was on the order of W/(m2-K), regardless of heater orientation. In addition, the heat lost due to conduction in the upward-facing heater pedestal was estimated using both experimental and numerical results, and was found to be 1.0 greater or less than (percent of heat loss due to conduction in glass heater pedestal assembly) greater or less than 2.5%.