The study of nanofluid properties, nanoparticle characterization, flow visualization, and validation of natural convection cavity setup

Abstract

In this study alumina and iron oxide nanoparticles of 13 nm and 50–100 nm, average particle size (APS) are used. The transmission Electron Microscopy (TEM) image has confirmed the size. X-ray Diffraction (XRD) analysis has confirmed impurity-free nano-powder and its type. Here concentration (ppm), electrical conductivity (COM – 80 TDS), pH of the sample (pH tester), and all the major thermo-physical properties e.g. specific heat capacity, thermal conductivity (25 % increase at 0.1 % v/v to the base fluid DM water), viscosity (maximum 1.7 % variation to the mean value), and specific gravity (remains almost constant) are measured at equilibrium conditions. A few flow visualization study of alumina and iron-oxide nanoparticles show their movement in the base fluid. Alumina particles mainly move in a static fluid due to gravity and iron oxide nanoparticle under a rotary magnetic field may rotate like amebae or circular motion around their axis as well the axis of the field and move forward at the bottom of the cavity. The natural convection cavity measured parameters are validated using two non-dimensional parameters and compared with two benchmark papers. It is found that most of the measured data points lie between the two reference curves.