Bioconvection analysis of EMHD and dissipative Williamson nanofluid over a three dimensional Riga plate with Joule heating effect

Abstract

ABSTRACT The current study investigates the weakly hydromagnetic and bioconvection nanofluid flow of Williamson fluid, which conveys gyrotactic microorganisms, over a three-dimensional Riga surface. The primary objective is to stabilize biological, mechanical, and thermal systems through the introduction of exponentially decaying rheology in both the momentum and energy equations, known as the electro-magneto-hydrodynamic actuator (EMHD). As such, the working fluid is assumed to be dissipative, with significant consideration given to the magnetic Reynolds number and a higher-order reaction rate. To simplify the phenomenon of suspended nanoparticles’ bioconvection, an appropriate similarity transformation is applied, converting the system of partial differential equations (PDEs) into systems of ordinary differential equations (ODEs). To analyze the governing flow parameters, the numerical approach, Galerkin Weighted Residual Method (GWRM), is employed. The results are presented through tables and graphs, providing valuable insights. The findings of the study highlight that Hartmann number improves the weak movement of the Williamson fluid, thermophoresis number positively affects all flow distributions. Moreover, the temperature field is influenced by Brownian motion, leading to inflation, while the concentration field experiences a decrease due to a lower number of fluid particles available for reaction. Furthermore, higher buoyancy forces indicate significant fluid movement, resulting in a reduction in the Williamson fluid chemical reaction rate.