Electrical field combined nanofluid to enhance the thermal performance of vertical open microgrooves heat sink

Abstract

• Electrical field combined nanofluid shows a 32.8% decrease of wall temperature. • Nanofluid combined electric field causes a circular low temperature area in the wall. • Electrical field affects meniscus, CPL and nanoparticle, resulting in enhancement. The open microgrooves heat sinks pose a promising application in the future of electronic devices cooling. However, there are problems with insufficient supply of working fluid and easy drying. In this paper, the above problems are solved by electrical field combined with nanofluid. The capillary characteristic and thermal performance of the open vertical microgrooves heat sink in the non-uniform electrical field with Al 2 O 3 /water nanofluid were experimentally studied. Experimental results show that at the input power of 4W, optimal concentration of 0.006 nanofluid and electric field cause a wall temperature reduction of 16.9 o C, which is about 24% lower than the pure base fluid under electric field. Moreover, a circular low-temperature phenomenon is found by the infrared imager. Thermal enhancement is attributed that electrical field causes fluctuations in the meniscus, enhanced capillary wetting length (CPL) and directional motion of particles. The long CPL of nanofluid is subjected to stronger electrical field force resulting in an intense evaporation, which poses a circular low temperature region.