Heat transfer investigation of laminar developing flow of nanofluids in a microchannel based on Eulerian-Lagrangian approach

In this article, laminar forced convection of nanofluids in a parallel plate microchannel under constant wall temperature is numerically investigated. A Eulerian–Lagrangian two‐phase method is employed to simulate the flow and heat transfer of nanofluid in the microchannel. Navier–Stokes equations were solved using a finite difference method based on the projection algorithm while a Runge–Kutta method have been used to solve Lagrangian equations of the particle phase. A parallel code is developed on a cluster of processors which indicates a good performance to solve an Eulerian–Lagrangian problem. The convective heat transfer coefficient of nanofluids is better than the base fluid particularly in the entrance region. The results based on two phase modelling, show a slightly greater improvement in the heat transfer coefficient in comparison to the homogeneous single‐phase nanofluid method. The obtained results show that the heat transfer enhancement increases as the nanoparticles volume fraction increases, and decreases with the Reynolds number for Cu–water nanofluid, while the alumina–water nanofluid have a different behaviour. A comparison of two different nanofluids showed the importance considering all of the nanofluid's properties not just thermal conductivity.