09. Heat and Mass Transfer

Nanofluid is composed of base fluid and nanoparticles with sizes ranging from 1 to 100 nm. Common nanoparticles include metals, metal oxides, and carbon nanotubes, while base fluids are water, ethylene glycol, and oil. This study aims to establish a mathematical and physical model to investigate the flow characteristics of nanofluid, and provide numerical solutions for theoretical research on this topic. This study explores the convective, magnetic field, Darcy effect, thermal radiation, Brownian diffusion, and thermophoresis interactions when nanofluid containing carbon nanotubes in a water base fluid flowing over a horizontal plate through a porous medium. The governing equations include the continuity equation, momentum equation, energy equation, and concentration equation. These equations are solved using the Runge-Kutta integration combined with the shooting method after similarity transformation. The study discusses the impact of the Darcy effect on boundary layer development when nanofluid flow through a porous medium. As the Darcy number, Da increases, the flow velocity decreases, leading to higher temperature and concentration within the boundary layer. As increase in the nanoparticle volume fraction, φ results in a thicker temperature boundary layer and decrease in concentration at the wall. With a rise in the thermophoretic parameter, Nt will enhance the thermophoretic effect to push nanoparticles outward. An increase in the Brownian motion parameter, Nb will accelerate the mass transfer rate near the wall and produce a larger concentration gradient. In addition, as the Schmidt number, Sc increases, nanoparticle concentration tends to accumulate near the wall.