Effects of thermal radiation, viscous and Joule heating on electrical MHD nanofluid with double stratification

• Published in: Chinese journal of physics (Taipei) 2017-06, Vol.55 (3), p.630-651
• Main Authors: Shagaiya Daniel, Yahaya, Abdul Aziz, Zainal, Ismail, Zuhaila, Salah, Faisal
• Format: Article
• Language: English
• Subjects: Doubly stratified flow; MHD nanofluid; Mixed convection; Thermal radiation; Viscous dissipation
• ISSN: 0577-9073
• DOI: 10.1016/j.cjph.2017.04.001

•This paper analyses doubly stratified flow of electrical MHD nanofluid.•A similarity transformation is used then solved by Keller box method.•Electric field resolves sticking effects leads by magnetic field.•Effects of doubly stratification on heat convection and mass diffusion are examined.•The comparison is also made with the existing published data. The investigation is made to study the combined effects of thermal radiation, viscous dissipation and Joule heating in steady two-dimensional electrical magnetohydrodynamic boundary layer flow of nanofluids using Buongiorno's model over a permeable linear stretching sheet. The system of transport equation incorporate the effects of Brownian motion, thermophoresis, thermal and concentration stratifications in the presence of nano energy conversion emerging parameters. A similarity transformation is implemented to reduce the boundary layer flow equations to a system of nonlinear ordinary differential equations, then solved by implicit finite difference scheme. The computation has been investigated for certain range of values required emerging parameters M(0 ≤ M ≤ 2.5), E1(0 ≤ E1 ≤ 1.0), s(−0.4≤s≤1.0), λ(0.1 ≤ λ ≤ 2.0), N(0.1 ≤ N ≤ 1.0), Rd(0 ≤ Rd ≤ 1.0), Nb(0.1 ≤ Nb ≤ 0.5), Nt(0.1 ≤ Nt ≤ 0.5), Ec(0 ≤ Ec ≤ 0.8), st(0 ≤ st ≤ 0.7), Le(2 ≤ Le ≤ 10), sc(0 ≤ sc ≤ 0.7). Velocity field enhances with the electric field and mixed convection but decreases with fluid suction. Electric field resolved the sticking effects due to the magnetic field. Thermal and concentration stratifications lead to a reduction in temperature and nanoparticle concentration. Heat conduction is sensitive to an increase in an electric field, thermal radiation and viscous dissipation. The rate of heat and mass transfer reduces by increasing thermophoresis and thermal stratifications and it increases for larger values of suction. Numerical values are obtained for the skin friction, local Nusselt and Sherwood number for different involving parameters tabulated and examined. We compare the present numerical solution in limiting sense with previously published investigation presented and examined reveals good agreement.