Mixed Convection Analysis in Lid-driven Cavity with Sinusoidally Curved Bottom Wall Using CNT-Water Nanofluid

摘要

Mixed convection in a lid-driven enclosure with a curved bottom wall has been investigated using CNT (Carbon Nanotube)-water nanofluid in this paper. The curvature of the bottom wall follows the sine function. Studies have been made with different amplitudes (λ = 0.05, 0.1, 0.15) of the sine function hence wall curvature. The curved wall at the bottom is heated and the top wall is kept at a relatively low temperature. Left vertical and right vertical surface are assumed to be adiabatic. Top wall has been moving at a constant lid velocity U_0 at right direction. Galerkin method of FEA (Finite Element Analysis) has been used to solve the governing equations. Different parameters like Richardson number (Ri = 0.1 ～ 10) at a fixed Reynolds number (Re = 100), solid volume fraction of CNT particle (Φ = 0 ～ 0.09) are used to observe better heat transfer rate. Streamlines, isothermal lines and average Nusselt number plots are included to discuss the result of the investigation. A 2D plot between average Nusselt number and solid volume fraction of CNT-water nanofluid is also given to analyse heat transfer rate. It is observed that higher value of Richardson number shows better heat transfer rate. Finally, the paper concludes that better heat transfer is achieved at higher amplitude (λ = 0.15) of curved surface at higher solid volume fraction (Φ = 0.09).