The impact of Newtonian heating on magnetic Casson nanofluid flow with variable consistency over a variable surface thickness

K. Ahmad¹ - S. S. P. M. Isa^2,3 - Z. Wahid¹ - Z. Hanouf⁴

¹ Department of Science in Engineering, Kulliyyah of Engineering, International Islamic University Malaysia, 50728 Gombak, Kuala Lumpur Malaysia
² Laboratory of Computational Sciences and Mathematical Physics, Institute for Mathematical Research, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
³ Centre of Foundation Studies for Agricultural Science, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia
⁴ Department of Mechanical Engineering, University of Bahrain, 32038, Sakheer, Kingdom of Bahrain

Abstract
A boundary layer flow of Casson nanofluid passing through a heated slab due to Newtonian heating with inconstant viscosity streaming over a varying surface thickness is investigated. The fluid flow equations which are non-linear PDE are converted to non-linear ODE by suitable similarity transformation. A numerical approach is used to solve those equations along with several values of pertinent parameters such as the velocity power constant m, the magnetic parameter H, the fluid viscosity parameter Ω, the Biot number Bi and the surface thickness parameter α, using the finite difference method. Detailed impacts of these parameters on the surface are thoroughly discussed and necessary tables and graphs are plotted for this reason. Comparison with previously reported results is made for the sake of validation. The velocity power constant m is observed to increase the −f′′(0) value only for positive fluid viscosity Ω, to increase the surface temperature θ(0) and to decrease −ϕ′(0) except for Ω=-3. Tables 1, Figs 10, Refs 21.