Effect of moving walls on heat transfer and entropy generation in a nanofluid-filled enclosure

Abstract

In this work, a numerical investigation of mixed convection has been carried out in a two-sided lid-driven enclosure filled with copper–water nanofluid. Three different cases have been discussed depending on the direction of moving vertical walls to analyze the behavior of fluid flow and heat transfer in nanofluid. The buoyancy effects are incorporated using two discrete heat sources placed on the bottom wall maintaining a fixed distance from both the side walls. The stationary part of the bottom wall is kept insulated while other walls are maintained at constant low temperature. A two-dimensional computational visualization technique has been employed to demonstrate the main findings of the presented work. The effect of higher nanoparticle volume fraction (up to 20%) with variations of Reynolds number and Richardson number is studied to find the rate of heat transfer. The results are presented using streamlines, isotherms, and energy flux vectors. The thermodynamic optimization of the system is analyzed by using Nusselt number and entropy generation.