Numerical Heat Transfer by Nanofluids in a wavy walls Microchannel using Dispersion Method

In this paper, conjugate heat transfer in wavy microchannels filled with nanofluid is studied numerically. To simulate the nanofluids, dispersion and homogeneous methods in single-phase model and Eulerian-Lagrangian method in two-phase model are used. Homogeneous method underestimates the experimental results. Then, nanofluid simulated by two-phase model using an Eulerian-Lagrangian approach. Then its results are used to find the unknown parameter in the conduction relation of nanofluid in dispersion method. Nanofluids are water-Cu or water-Al2O3 suspensions with a particle diameter of 100-150nm and a volume fraction of up to 2%. The three-dimensional governing equations including continuity, Navier-Stokes and energy equations are solved by the well-known SIMPLE method. The governing equations for particles are solved by a 4th order Runge-Kutta algorithm. due to the 3-D governing equation four equations includinf velocity components and energy should be solved for all particles. The computer program has been written in parallel processing method (MPI). Then a super computer with several CPU,s should be used. Using dispersion method is as simple as homogeneous method but has accuracy as two-phase Eulerian-Lagrangian method.