Computation of non-isothermal thermo-convective micropolar fluid dynamics in a Hall MHD generator system with non-linear distending wall

Beg, OA; Ferdows, M; Karim, ME; Hasan, MM; Beg, TA; Shamshuddin, M; Kadir, A

Abstract

A theoretical model for steady non-isothermal convective heat transfer in non-Newtonian magnetized
micropolar gas flow from a non-linear stretching/contracting wall in the presence of strong magnetic
field is presented, as a simulation of an MHD (magnetohydrodynamic) Hall energy generator.
Subsonic flow is considered, and compressibility effects neglected. The strength of the magnetic
field which is applied in the general case obliquely to the wall is sufficient to invoke the collective
effects of Hall current and Ohmic heating (Joule dissipation). Viscous heating is also included in the
energy balance. Deploying similarity transformations, the governing equations are normalized into
nonlinear ordinary differential equations with associated boundary conditions. The non-linear
boundary value problem thus posed is then solved computationally with Nachtsheim-Swigert
iteration technique along with the fourth-fifth order Runge-Kutta integration method (RKM).
Verification of solutions is obtained with the semi-analytical Homotopy analysis method (HAM).
Further validation is conducted with the semi-numerical Adomian Decomposition Method (ADM).
In both cases excellent agreement is obtained with the Runge-Kutta shooting quadrature solutions.
Additional validation is conducted with earlier Newtonian studies in the absence of micropolar, Hall
current and dissipation effects. The influence of local Grashof number, local Hartmann number,
Eringen microrotational parameter, Eringen coupling vortex parameter, Prandtl number and Eckert
number on non-dimensional velocity components (primary, secondary and angular) and temperature
within the boundary layer are graphically illustrated and interpreted at length. Furthermore, the
effects of the thermophysical (e.g. non-isothermal power law index), electromagnetic parameters
(e.g. Hall parameter) and geometric parameter (wall extension/contraction parameter) on the skinfriction coefficient (i.e. primary and secondary shear stress and wall couple stress) and surface heat
transfer rate (Nusselt number) are evaluated. The study is relevant to near wall transport phenomena
in novel MHD Hall power generators.

Citation

Beg, O., Ferdows, M., Karim, M., Hasan, M., Beg, T., Shamshuddin, M., & Kadir, A. (2020). Computation of non-isothermal thermo-convective micropolar fluid dynamics in a Hall MHD generator system with non-linear distending wall. International Journal of Applied and Computational Mathematics, 6, 42. https://doi.org/10.1007/s40819-020-0792-y

• Journal Article Type: Article
• Acceptance Date: Feb 15, 2020
• Online Publication Date: Mar 7, 2020
• Publication Date: Mar 7, 2020
• Deposit Date: Feb 18, 2020
• Publicly Available Date: Mar 7, 2021
• Journal: International Journal of Applied and Computational Mathematics
• Print ISSN: 2349-5103
• Electronic ISSN: 2199-5796
• Publisher: Springer
• Volume: 6
• Pages: 42
• DOI: https://doi.org/10.1007/s40819-020-0792-y
• Publisher URL: https://doi.org/10.1007/s40819-020-0792-y
• Related Public URLs: https://www-springer-com.salford.idm.oclc.org/journal/40819