Fluid Flow in Cylindrical Ducts with Nanoparticles

Abstract

In present dissertation, two papers are discussed. Firstly, the magneto-hydrodynamics (MHD) movement of copper (Cu) nanoparticles under the action of water with an oscillating pressure gradient among two concentric ducts is reviewed. Nanoparticles addition is assumed to have significantly improved thermal performance near surface for turbulent and laminar flow. The standard governing equations are partial dif- ferential equations and comprises effective thermal conductivity, base fluid viscosity and thermophysical characteristics of water based Cu nanoparticles. The exact so- lutions are obtained in the form of the modified Bessel functions of first and second kind. Pressure difference, vorticity, temperature and velocity distribution are analyzed graphically for several flow controlling parameters. Outcomes affirmed that velocity, temperature and heat transfer rate can be modified with the help of external magnetic field and nanoparticles addition. Secondly, considering the magnetic field, the flow and heat transfer of nanofluids through a stretching cylinder is discussed. A similarity so- lution is suggested, which transforms the constitutive equations into the set of ODEs. Various type of nanoparticles like alumina (Al2O3), copper (Cu), silver (Ag), and tita- nium oxide (TiO2) are considered, alongwith water (H2O) as a base fluid. Significant fluid dynamics concepts such as heat transfer rate, skin friction coefficient, velocity distribution, Nusselt number etc. are analyzed and plotted graphically. Furthermore,radiation effects on heat transfer and MHD flow of nanofluids in a porous medium is analyzed. The solution of the system of equations is evaluated numerically by MAT- LAB function bvp4c. The impact of flow controlling parameters like heat generation or absorption parameter (Q), porosity parameter (K), thermal radiation (Nr), and vol- ume fraction (ϕ) on temperature and velocity profiles for Cu-water nanoparticles are investigated. The graphical and tabular results demonstrates that these parameters provide a remarkable change in Nusselt number and skin friction coefficient.