Forced Convective Boiling of a Fluorocarbon Liquid in Reduced Size Channels--an Experimental Study

The present paper reports the results of an experimental study of forced convection boiling heat transfer from a 2 cm x 2 cm simulated chip to a fluorocarbon coolant (FX-3250) in a parallel-plate channel. The experimental parameters were the channel height (1 and 5 mm), the surface geometry of the simulated chip (flat and microfinned), and the coolant velocity (0.125-4 m/s). Longitudinal microfins (0.5 mm high x 0.5 mm wide) on the finned chip increased the actual surface area to about twice that of the flat surface. Attention was focused on the data of the 1-mm high channel. When compared with the flat chip data on the footprint area basis, the microfins produced 40% of heat transfer enhancement at coolant velocities less than 1 m/s; however, the enhancement diminishes at higher velocities. The boiling curves of the finned chip, based on the actual area, seem to reflect that there is an effect due to the bypassing of flow through the cross-section over the fins. For both the flat chip and the finned chip...