Boiling on microconfigured surfaces in liquid nitrogen

Abstract Measurementsare given for pool boiling on 1.27 by 1.27cm vertical silicon surfaces in liquid nitrogen. The microfeatures on the test surfaces were 10μm base length, 7.1μm deep. The center to center spacing of the inverted pyramids was 20, 40, and 60μm for the three different site densities tested. The site density of the 20, 40, and 60μm surfaces was 2.5 × 10 5 , 0.625 × 10 5 , and 0.278 × 10 5 per cm 2 , respectively. The heat transfer performance, at a given wall-superheat, was closely proportional to the site density. No temperature hysteresis or overshoot arose at the onset of nucleation.