Natural Convection Characteristics of Copper-Water Nano Fluid with Two Heat Sources at the Bottom Surface in a Square Enclosure-A Numerical Study

Abstract

Natural convective fluid flow and heat transfer in a square cavity filled with Copper (Cu) nano particles, mixed in a base fluid (water) has been numerically studied using finite volume method. The Semi Implicit Method for Pressure Linked Equations (SIMPLE) algorithm has been used to solve the transport equations (momentum and energy). Two constant temperature heat sources of same magnitude are placed on bottom surface and the two vertical surface temperatures are kept cold, while the top surface is maintained adiabatic. The influence of Rayleigh number (RaN) (varied from 1000 to 10 6) and nanoparticle volume fraction (Φ = 0%, 5%, 10%, 15% and 20%) on fluid and heat flow characteristics has been numerically investigated and presented in the form of streamlines, velocity vectors, constant temperature lines, vertical velocity component at mid horizontal line, local and average Nusselt number. The obtained results indicate, for higher values of RaN (RaN=10 5 and 10 6) and volume fractions of nanoparticles, there is a significant increase in vertical velocity component, local and average Nusselt numbers due to increase in buoyancy forces and thermal conductivity of nanofluid.