Bioconvection And Activation Energy Effects In Mhd Flow Of Non Newtonian Nanofluids Over A Permeable Stretching Sheet

Abstract

Bioconvection refers to the phenomenon in which random patterns of cell concentration newlineand gravitational instabilities arise when motile microorganisms swim upward on average due newlineto their density being slightly higher than that of water. The term quotbioconvectionquot was newlineintroduced by James Henry Platt to draw attention to the streaming patterns observed in dense newlinecultures of free-swimming species. Microorganisms are influenced by various stimuli, newlineincluding gravity, light, oxygen, and fluid currents, which guide their taxis, causing them to newlinemove toward or away from these stimuli. This behavior leads to hydrodynamic instability, newlineresulting in the formation of tightly packed communities of microorganisms. Bioconvection is newlinean example of how collective dynamics can be more potent than individual movements and can newlinebe modelled using fluid dynamics equations. newlineThis thesis investigates the bioconvection of nanofluid flow over a stretching sheet newlinecontaining gyrotactic microorganisms subject to varying boundary conditions. It explores the newlineeffect of these boundary conditions on flow properties, considering factors such as heat source newlineor sink, viscous dissipation, Joule heating, thermal radiation, and activation energy. The impacts newlineof thermophoresis and Brownian motion on concentration and temperature distributions are newlinealso considered. The bioconvection and thermal transfer dynamics in a permeable medium are newlinemodeled using the Boussinesq approximation. The governing equations are converted into newlinedimensionless form using appropriate non-dimensional variables and simplified through the newlineBVP4C and Homotopy Analysis Method (HAM). Temperature contours and stream function newlineprofiles are generated to compute the Nusselt, Sherwood, and motile density numbers. The newlineresults are presented visually through graphs and tables, ensuring a comprehensive newlineunderstanding of the problem. Key aspects and characteristics of the system are carefully newlineanalyzed.