Effects of single and multi-walled carbon nano tubes on water and engine oil based rotating fluids with internal heating

摘要

Three dimensional (3D) flow of a rotating Water and Engine Oil Based fluid is analyzed. Effects of nanometer (nm) sized Single (SWCNT) and multiwalled carbon nanotubes (MWCNT) are examined on flow and heat transfer characteristics. Thermofluid performance within Water and Engine Oil base fluid are investigated using thermal conductivity and viscosity of both single and multiple wall carbon nanotubes (CNTs) of similar volume. The governing partial differential equations are converted into nonlinear, coupled, ordinary differential equations which are solved numerically using a combination of Quasi-linearization and Chebyshev pseudo-spectral methods. Effects of relevant parameters on physical quantities are examined. The obtained results revealed an enhancement in temperature as well as corresponding thermal boundary layer thickness with volume fraction of both types of carbon nanotubes. Due to higher density and thermal conductivity, SWCNTs offer higher skin friction and Nusselt number. Engine oil base fluid depicted higher heat transfer rate and local skin friction than water based fluid for both type of carbon nanotubes. Residual error are plotted to check the accuracy of obtained results. Comparison with previously published literature is made and an excellent agreement is observed which validate our applied numerical scheme. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.