Numerical investigation on heat transfer enhancement inside a rectangular microchannel with vortex generator using TiO2, Cuo-water nanofluids

Article history Received: 16 December 2019 Accepted: 17 January 2020 Published Online: 31 March 2020 One of the innovative ways to improve heat transfer properties of heat exchangers, is using nanofluids instead of traditional fluids. Due to presence of metal and oxides of metal particles in nanofluids structure, they have better potential in different environments and conditions than conventional fluids and having higher thermal conductivity causes improvements in heat transfer properties. In this research flow of two different nanofluids through a rectangular microchannel containing a different number of longitudinal vortex generators (lvgs), has been investigated. Simulations conducted under laminar flow boundary condition and for varied Reynolds numbers of 100 to 250. Considered volumetric concentration in this paper is 1, 1/6 and 2/3 %. Results showed, nanofluids and the LVGs notably improve the heat transfer rates within the microchannel. havg improved with increasing the nanoparticles volume concentrations and Reynolds number, while the opposite trends recognized for pressure drop. havg improved for 4 to 12 and 9 to 18% for TiO2 and CuO nanofluids, respectively for different volume concentrations in simple microchannel. For lvg-enhanced microchannel the amount of improvements is about 9-14 and 5-10% for CuO and TiO2, respectively. Also using vortex generators alone improved havg for 15-25% for different number of lvgs.