Effect of heater material and thickness on the saturated pool nucleate boiling curve

The heater effects on the saturated nucleate boiling curve were investigated using a previously developed numerical model. Two generally used heater materials, copper and nickel, were considered for heater thicknesses varying from 0.012 to 4 mm. A parametric study is presented to identify the most influential parameters. Results show that for a given heat flux, the nucleate boiling heat-transfer coefficient (HTC) for a copper heater is higher than the HTC for a nickel heater. Furthermore, the difference between the boiling curves for copper and nickel is a function of the surface topography. In general, the boiling curve for a given heater material shifts to the left with decreasing heater thickness. This result agrees with most of the available studies, with the exception of one. Our analysis also shows that, for rougher surfaces over a nickel heater, there is an increase in the HTC with decreasing heater thickness. Reducing the bubble departure diamter with decreasing thickness in our simulations, we were able to more clearly observe the increasing trend of the HTC with decreasing heater thickness for relatively rough surfaces.