Entropy Generation and Mixed Convection of a Nanofluid in a 3D Wave Tank with Rotating Inner Cylinder

Abstract

The generation of entropy and mixed convection in a nanofluid-filled 3D wavy tank containing a rotating cylinder is investigated. The top wavy surface of the tank is heated and all vertical surfaces are assumed to be adiabatic, while the bottom horizontal surface remains isothermally cold. The tank contains a solid cylinder and is saturated with an Al2O3–water nanofluid. The numerical simulations using the FEM are performed for the Richardson number (0.01≤Ri≤100), nanoparticle volume fraction (0≤ϕ≤0.04) and number of oscillations (0≤N≤4). The numerical results of the present work are given in terms of 3D streamlines, isotherms and local entropy generation, as well as average heat transfer and Bejan number. The results show that for low values of the Richardson number and oscillation, heat transfer enhancement can be achieved by increasing the nanoparticle volume fraction.

Keywords

• combined convection
• entropy generation
• rotating inner cylinder
• 3D wave tank
• nanofluid