Heat and mass lines visualization techniques for heat and mass flow in double-diffusive natural convection utilizing Cu-water nanofluid

Abstract

Most of the recent works indicate that the isotherms, isosolutes, and streamlines are commonly used to study the thermosolute natural convection phenomena. Although the fluid flow is effectively illustrated by the use of streamlines (to visualize fluid flow), isotherms (to visualize temperature distribution), and isosolutes (to visualize solute distribution) cannot represent the 'heat flow' and 'solute flow' as the isotherms and isosolutes indicate only the spatial distribution of temperature and solute respectively. A visualization tool is important to understand the heat and solute flow during thermosolute convection. In addition, it is not easy to visualize convection heat and solute transfers due to the presence of both conduction and convection. In this work, two dimensional laminar thermosolute natural convection has been numerically investigated in a differentially heated and soluted square enclosure in the presence of cu-water nanofluid. To enhancing the heat transfer, nanofluids are quite helpful. The left and right vertical walls are considered as higher and lower temperatures and solute, respectively whereas the horizontal walls are being kept adiabatic and non-diffusive. The mathematical formulation of heat and mass functions have been done, and based on these functions, the heat and mass lines contours have been drawn to investigate the behavior of heat and solute in the cavity. The flow governing equations have been solved using a finite difference method together with successive over-relaxation (SOR) technique after converted into the vorticity-stream function form. A comparison of isotherms with heatlines and isosolute with masslines has been done in detail.