Homotopy study of magnetohydrodynamic mixed convection nanofluid multiple slip flow and heat transfer from a vertical cylinder with entropy generation

Nisha Shukla ^a,  Puneet Rana ^a,*, O. Anwar Bég ^b,  Bani Singh ^a,  A. Kadir ^c

a. Department of Mathematics, Jaypee Institute of Information Technology, A-10, Sector-62, Noida 201307, Uttar Pradesh, India
         b. Fluid Mechanics, Propulsion and Nanosystems, Aeronautical and Mechanical Engineering, School of Computing, Science & Engineering, University of Salford, Newton Building, M54WT, UK
         c. Materials and Corrosion, Petroleum and Gas Engineering, School of Computing, Science & Engineering, University of Salford, Newton Building, M54WT, UK  

Abstract: Stimulated by thermal optimization in magnetic materials process engineering, the present investigation investigates theoretically the entropy generation in mixed convection magnetohydrodynamic (MHD) flow of an electrically-conducting nanofluid from a vertical cylinder. The mathematical includes the effects of viscous dissipation and second order velocity slip and thermal slip. The cylindrical partial differential form of the two-component non-homogenous nanofluid model has been transformed into a system of coupled ordinary differential equations by applying similarity transformations. The effects of governing parameters with no-flux nanoparticle concentration have been examined on important quantities of interest. Furthermore the dimensionless form of the entropy generation number has also been evaluated using the powerful homotopy analysis method (HAM). The present analytical results achieve good correlation with numerical results. Entropy is found to be an increasing function of second order velocity slip, magnetic field and curvature parameter. Temperature is elevated with increasing curvature parameter and magnetic parameter whereas it is reduced with mixed convection parameter. The flow is accelerated with curvature parameter but decelerated with magnetic parameter. Heat transfer rate (Nusselt number) is enhanced with greater mixed convection parameter, curvature parameter and first order velocity slip parameter but reduced with increasing second order velocity slip parameter. Entropy generation is also increased with magnetic parameter, second order slip velocity parameter, curvature parameter, thermophoresis parameter, buoyancy parameter and Reynolds number whereas it is suppressed with higher first order velocity slip parameter, Brownian motion parameter and thermal slip parameter.

Keywords: Magnetohydrodynamic (MHD); Nanofluid; Vertical cylinder; Homotopy analysis method (HAM); Second order slip; Entropy; Curvature