A novel combined model of discrete and mixture phases for nanoparticles in convective turbulent flow

Abstract

In this study, a new combined model presented to study the flow and discrete phase features of nano-size particles for turbulent convection in a horizontal tube. Due to the complexity and also many phenomena involved in particleliquid turbulent flows, the conventional models are not able to properly predict some hidden aspects of the flow. Therefore, Brownian motion is implemented in discrete phase model to predict the migration of the particles as well as energy equation has modified for particles. Then, the final results are exported to the mixture equations of the flow. The effects of the mass diffusion due to thermophoresis, Brownian motion and turbulent dispersion are implemented as source terms in equations. The results are compared with the experimental measurements from literature and are adequately validated. The accuracy of predicted heat transfer and friction coefficients are also discussed versus measurements. The migration of the particles toward the centre of the tube is properly captured. The results show the non-uniform distribution of particles in turbulent flow due to strong turbulent dispersion. The proposed combined model can open new viewpoints of particle-fluid interaction flows.