Natural convective nanofluid flow characteristics with Brownian motion effect in an annular space between confocal elliptic cylinders

The principal aim of this work is to study numerically the natural convection in an annular space between confocal elliptic cylinders. The Brownian motion was added based on the thermal conductivity model and the simulation was carried out using finite volume control method. Various nanofluids with different volume concentrations were undertaken ranging from 2% to 6% and various Rayleigh numbers were tested for different particles. The isotherms and stream function are presented and it was clearly seen that by increasing the Rayleigh number, the heat transfer rate increases on the domain. On the other hand it was noticed that the heat transfer enhancement is less sensitive to the nanoparticles when the Brownian motion was considered