MHD mixed convection analysis in an open channel by obstructed Poiseuille flow of non-Newtonian power law fluid

• Main Authors: Rabbi, Khan Md, Rakib, Tawfiqur, Das, Sourav, Mojumder, Satyajit, Saha, Sourav
• Format: Conference Proceeding
• Language: English
• Subjects: Boundary conditions; Computational fluid dynamics; Convection; Entrances; Fluid flow; Galerkin method; Hartmann number; Heat transfer; Laminar flow; Magnetohydrodynamics; Newtonian fluids; Non Newtonian fluids; Open channels; Power law; Pseudoplasticity; Reynolds number; Richardson number; Viscosity
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.4958421

This paper demonstrates magneto-hydrodynamic (MHD) mixed convection flow through a channel with a rectangular obstacle at the entrance region using non-Newtonian power law fluid. The obstacle is kept at uniformly high temperature whereas the inlet and top wall of the channel are maintained at a temperature lower than obstacle temperature. Poiseuille flow is implemented as the inlet velocity boundary condition. Grid independency test and code validation are performed to justify the computational accuracy before solving the present problem. Galerkin weighted residual method has been appointed to solve the continuity, momentum and energy equations. The problem has been solved for wide range of pertinent parameters like Richardson number (Ri = 0.1 - 10) at a constant Reynolds number (Re = 100), Hartmann number (Ha = 0 - 100), power index (n = 0.6 - 1.6). The flow and thermal field have been thoroughly discussed through streamline and isothermal lines respectively. The heat transfer performance of the given study has been illustrated by average Nusselt number plots. It is observed that increment of Hartmann number (Ha) tends to decrease the heat transfer rate up to a critical value (Ha = 20) and then let increase the heat transfer performance. Thus maximum heat transfer rate has been recorded for higher Hartmann number and Rayleigh number in case of pseudo-plastic (n = 0.6) non-Newtonian fluid flow.