Experimental investigation of heat transfer for pulsating flow of GOPs-water nanofluid in a microchannel

Abstract

The effects of mass fraction (φ) of graphene oxide particles (GOPs) and pulsating frequency (f) on heat transfer and pressure drop in a microchannel with arrayed pin-fins were experimentally investigated. Five different mass fractions of graphene oxide nanofluids were prepared and used as working fluids. Experiments were performed under the condition that the pulsating frequency was from 1 to 5 Hz, the mass fractions was from 0.02% to 0.2% and the average Reynolds number was 272, 407 and 544. The results show that the heat transfer is enhanced significantly when the frequency is in the range of 2 to 5 Hz. For the frequency of 1 Hz, the pulsating flow has a negative effect on temperature uniformity. With the increase of mass fraction, the heat transfer performance is improved while no significant change is found in pressure drop. The pulsating flow leads to a significant enhancement of pressure drop for frequency at 2 Hz. The combination of pulsating and nanofluid can obtain higher heat transfer efficiency under limited size of microchannel heat sink and low inlet Reynolds numbers. This study has a certain guiding significance for the development of microchannel liquid cooling technology.