Numerical simulation of natural convection of a water-based nanofluid

We simulated steady and unsteady natural convection flows of a nanofluid in a square cavity. If the particle distribution is perfectly uniform there is a reduction of the heat transfer rates of about 1% in comparison with those corresponding to the pure liquid. The Lagrangian tracking of the particles shows that there is no preferential concentration of particles. However the local instantaneous fluctuations of the particle concentration induced by the tracking of a finite number of particles produce reductions of the heat transfer rates of about 2-3%. The particle migration model used predicts negligible non-uniformities in the particle distribution.