NUMERICAL INVESTIGATION ON THE TURBULENT FLOW CHARACTERISTIC OF NANOFLUIDS IN A HORIZONTAL CIRCULAR TUBE

Turbulent flow characteristic of TiO2-water nanofluids inside a horizontal circular tube is studied numerically by single-phase model, mixture multiphase model and Eulerian-Eulerian multiphase model. The flow characteristic is accounted from micro-flow aspect in order to reveal the mechanism of heat transfer enhancement in nanofluids. A new empirical correlation of nanoparticle viscosity has been proposed for multiphase models, which is much more precise than traditional empirical models. The presence of nanoparticles intensified local micro-flow and improved overall turbulence intensity significantly. The current study suggests that a thorough understanding on flow characteristics of nanofluids is essential for proposing mathematical description nanofluids flow.