MHD mixed convection analysis of non-Newtonian power law fluid in an open channel with round cavity

• Main Authors: Bose, Pritom, Rakib, Tawfiqur, Das, Sourav, Rabbi, Khan Md, Mojumder, Satyajit
• Format: Conference Proceeding
• Language: English
• Subjects: Computational fluid dynamics; Configuration management; Convection; Fluid flow; Fluids; Galerkin method; Hartmann number; Heat transfer; Magnetohydrodynamics; Newtonian fluids; Non Newtonian fluids; Open channels; Power law; Richardson number; Shear thickening (liquids); Thickening; Viscosity
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.4984686

In this study, magneto-hydrodynamic (MHD) mixed convection flow through a channel with a round cavity at bottom wall using non-Newtonian power law fluid is analysed numerically. The cavity is kept at uniformly high temperature whereas rest of the bottom wall is insulated and top wall of the channel is maintained at a temperature lower than cavity temperature. Grid independency test and code validation are performed to justify the computational accuracy before solving the present problem. Galerkin weighted residual method is appointed to solve the continuity, momentum and energy equations. The problem is solved for wide range of pertinent parameters like Rayleigh number (Ra= 103 – 105), Hartmann number (Ha= 0 - 60) and power law index (n= 0.5 – 1.5) at constant Richardson number Ri= 1.0. The flow and thermal field have been thoroughly discussed through streamline and isothermal lines respectively. The heat transfer performance of the given study is illustrated by average Nusselt number plots. Result of this investigation indicates that heat transfer is highest for dilatant fluids at this configuration and they perform better (47% more heat transfer) in absence of magnetic field. The retardation of heat transfer is offset by shear thickening nature of non-Newtonian fluid.