Confined impinging slot jets in porous media with nanofluids

In this paper a numerical investigation on mixed convection in confined slot jets impinging on a porous media is accomplished. The working fluids are pure water or Al2O3/water based nanofluids and a single-phase model approach has been adopted in order to describe their behavior. A two-dimensional configuration is analized and different Peclet numbers and Rayleigh numbers are considered. The thermal non-equilibrium energy condition is assumed to execute two-dimensional simulations on the system. The examined foams are characterized by distinct values of pores per inch, PPI, equal to 5, 10, 20 and 40. The particle volume concentrations range from 0% to 4% and the particle diameter is equal to 30 nm. The target surface is heated by a constant temperature value, calculated according to the value of Rayleigh number. The distance of the target surface is five times greater than the slot jet width. The aim consists into study the thermal and fluid-dynamic behaviour of the system. Results show increasing values of the convective heat transfer coefficients for increasing values of Peclet number and nanoparticle concentration. Furthermore, the heat transfer coefficient presents a different behavior at varying PPI numbers for different Peclet numbers

NanoRound: A benchmark study on the numerical approach in nanofluids' simulation

Numerical simulation of nanofluid flows is of maximum importance for a large area of applications, especially in the solar energy technology. Even though a lot of numerical studies are available in the open literature, there is still a large debate in regard to the most appropriate approach when dealing with nanofluids. Plus, a precise simulation of the thermal fluid-solid system encompasses a profound understanding of the fundamental physical phenomena that appear in the nanofluid flow. In this idea, a number of simplifications and approaches are considered, and the aim of this benchmark study is to shed some light in the most suitable CFD approach when dealing with nanofluid flow. Finally, different approaches were considered by different research groups with relevant experience in CFD and are discussed accordingly and in connection with an experimental case that was chosen as a comparison. The current benchmark study was projected to be an ample reference for investigators interested in dealing with the numerical study of the nanofluids’ flow