Numerical study of thermal performance of yield stress rheological liquid under suspension of hybrid nanostructures: The finite element approach

Abstract

Enhancement of heat transfer employing nanofluids, studied numerically, observed profound effects in thermophysical and theological properties used in various applications such as avionics, laser diode, rocket nozzels and microelectronics. In this paper, the influence of thermal radiations and hybrid nanoparticles on free convection flow and heat transfer of Casson hybrid nanofluid over vertical plate is investigated. A mixture of pure water and ethylene glycol has been considered as a base Casson fluid while Copper oxide ([Formula: see text]) as nanofluid (single kind) and, Copper oxide ([Formula: see text]) and Silicon dioxide ([Formula: see text]) (double kind known as hybrid nanofluid) are disseminated in base Casson fluid mixture to be formed as hybrid nanofluid. The governing system of partial differential equations of the flow and heat transfer processes is converted to a system of well-posed coupled nonlinear ordinary differential equations by using the similarity transformations. The resulting system is solved using the Galerkin finite element (GFE) technique. The quadratic Lagrange polynomials are used as basis functions over the mesh of about 1000 to 2000 finite elements and the nonlinear system of order 6003 and upto 12003 is solved. The accuracy of developed numerical methods is confirmed by comparing their results with convection flow and heat transfer with nanoparticles. Thereafter, the said solutions are used to investigate the effects of thermal radiation, hybrid nanoparticle volume friction, Prandtl number, type of flow and heat transfer behavior. The innovative results of the present study reported higher velocities in suspensions with low sphericity particles and the radiation parameter is directly proportional to the temperature with the use of nano and hybrid nanoparticles. It has also been noted that the GFE method is a more stable numerical technique as compared with other existing analytic and semi-analytical methods.