A numerical study of magnetohydrodynamic transport of nanofluids from a vertical stretching sheet with exponential temperature-dependent viscosity and buoyancy effects

Akbar, NS; Tripathi, D; Khan, ZH; Beg, OA

Abstract

In this paper, a mathematical study is conducted of steady incompressible flow of a temperature-dependent viscous nanofluid from a vertical stretching sheet under applied external magnetic field and gravitational body force effects. The Reynolds exponential viscosity model is deployed. Electrically-conducting nanofluids are considered which comprise a suspension of uniform dimension nanoparticles suspended in viscous base fluid. The nanofluid sheet is extended with a linear velocity in the axial direction. The Buonjiornio model is utilized which features Brownian motion and thermophoresis effects. The partial differential equations for mass, momentum, energy and species (nano-particle concentration) are formulated with magnetic body force term. Viscous and Joule dissipation effects are neglected. The emerging nonlinear, coupled, boundary value problem is solved numerically using the Runge–Kutta fourth order method along with a shooting technique. Graphical solutions for velocity, temperature, concentration field, skin friction and Nusselt number are presented. Furthermore stream function plots are also included. Validation with Nakamura’s finite difference algorithm is included. Increasing nanofluid viscosity is observed to enhance temperatures and concentrations but to reduce velocity magnitudes. Nusselt number is enhanced with both thermal and species Grashof numbers whereas it is reduced with increasing thermophoresis parameter and Schmidt number. The model is applicable in nano-material manufacturing processes involving extruding sheets.

Citation

Akbar, N., Tripathi, D., Khan, Z., & Beg, O. (2016). A numerical study of magnetohydrodynamic transport of nanofluids from a vertical stretching sheet with exponential temperature-dependent viscosity and buoyancy effects. Chemical Physics Letters, 661, 20-30. https://doi.org/10.1016/j.cplett.2016.08.043

• Journal Article Type: Article
• Acceptance Date: Aug 19, 2016
• Online Publication Date: Aug 22, 2016
• Publication Date: Sep 16, 2016
• Deposit Date: Sep 1, 2016
• Publicly Available Date: Aug 22, 2017
• Journal: Chemical Physics Letters
• Print ISSN: 0009-2614
• Publisher: Elsevier
• Volume: 661
• Pages: 20-30
• DOI: https://doi.org/10.1016/j.cplett.2016.08.043
• Publisher URL: http://dx.doi.org/10.1016/j.cplett.2016.08.043
• Related Public URLs: http://www.journals.elsevier.com/chemical-physics-letters/