Heat transfer performance of a fractal silicon microchannel heat sink subjected to pulsation flow

Numerical simulation and experiment are conducted to study the heat transfer performance of a symmetrical fractal silicon microchannel network subjected to a pulsation flow. The distributions of pressure drop, temperature and the Nusselt number in the silicon microchannels are presented for different pulsation frequency. Compared to the steady flow case, the influences of pulsation frequency (0-40 Hz) and Reynolds number (1800-2800) on heat transfer enhancement are reported. For the low pulsation frequency (2-10 Hz) and high pulsation frequency (30-40 Hz), the heat transfer rate is higher than that for the moderate frequency (10-20 Hz) at the same Reynolds number. With the increase of the Reynolds number, enhancement factors decrease approximately from 40% to 5% for the investigated frequency range. (C) 2014 Elsevier Ltd. All rights reserved.