The Reasons of Differences between one phase and two phase Models of Nanofluids Heat Transfer Characteristics

in this paper, conjugate heat transfer in wavy microchannels filled with nanofluid is studied numerically. Homogeneous single-phase models underestimate the experimental results. Then, nanofluid simulated by two-phase model using an Eulerian-Lagrangian approach. 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. In one phase model there some supposes, one of them is that the velocty and temperature of a particle is equal to the velocity and temperature of its surrounding fluid. But the main suppose is that the particle distribution is homogeneous. Results show that the main reason of difference between the results of Homogeneous single-phase models and two-phase model is non-homogeneous particle distribution in the domain.