Experimental study of boiling heat transfer enhancement on micro-pin-finned surface with mechanical oscillation

An experimental study was made of boiling heat transfer on micro-pin-finned surfaces with mechanical oscillation device. Micro-pin-fins were fabricated on the surface of silicon chips by using dry etching method, and the size of the silicon chip is 10 mm×10 mm×0.5 mm. One smooth silicon chip and three kinds of micro-pin-finned surfaces with different fin size of 30 μm×60 μm(thickness, t × height, h) and 50 μm×60 μm and fin array arrangement (aligned and staggered) were tested. Absolute ethyl alcohol was used as the experimental liquid. A mechanical oscillation device with a circle plate located over the chips, which was supposed to enhance boiling heat transfer. All results indicated that mechanical oscillation did enhance boiling heat transfer in both single-phase region and nucleate boiling region. The critical heat flux was also increased by 20%. In addition, the boiling heat transfer of all micro-pin-finned chips were superior to smooth chip, which is mostly attribute to the increase of heater transfer area by micro-pin-fins.