Experimental study on enhanced nanofluid heat transfer limit and wetting predicted model in the microgroove under electric field

Abstract

The coupled effect of nanofluid and electric field contributes better heat transfer on the microgroove heat sink that has considerable prospects for addressing the heat dissipation of mobile devices. However, the wettability and the electric field enhanced heat transfer limit (EHL) of microgroove at high heat flux are still unknown. Thus, the wettability and EHL of Al2O3-water nanofluid in the vertical microgroove under electric field and the capillary wetting length prediction model were experimentally studied and developed. Accordingly, the maximum enhancement of electric field on nanofluids with optimal concentration would be reached at high heat flux, which is 1.6 times than that on pure water and it presents the wall temperature difference of 20.1 °C. Moreover, drying up phenomenon occurs at high nanofluid concentrations can be retarded by increasing the voltage. The increase of electric field reduces the clogging of nanoparticles to avoid the drying up phenomenon in microgrooves, which has greatly promoted heat transfer and reduced the wall temperature. The increase of electric field reduces the clogging of nanoparticles, and the replenished working fluid can retard the drying up. Besides, the prediction model of capillary wetting length agrees well with the experimental value.