Modeling and simulation of bioconvective casson nanofluid flow with activation energy and gyrotactic microorganisms with thermal radiation effects over curved surface

This study explores the flow dynamics of a Casson nanofluid over a curved stretchable surface, considering the combined effects of thermal radiation, activation energy, magnetic fields, and chemical reactions. To enhance heat and mass transfer rates, gyrotactic motile microorganisms are incorporated, inducing bioconvection a natural convection process driven by the self-motility of microorganisms. This mechanism significantly improves the transport properties of nanofluids. The mathematical model accounts for Brownian motion and thermophoretic effects, enabling a detailed investigation of microscale transport phenomena. The governing partial differential equations for momentum, energy, concentration, and microorganism density are transformed into a system of ODEs using similarity transformations. These ODEs are solved numerically via MATLAB's built-in bvp4c solver employing the shooting scheme. The impact of several dimensionless parameters on velocity, temperature, concentration, and microorganism density profiles is illustrated graphically. Additionally, key engineering metrics such as the skin friction coefficient, Sherwood number, Nusselt number, and motile microorganism density number are evaluated. The results indicate that higher Peclet and bioconvection parameters reduce thermal transport, whereas the Sherwood number increases with greater Brownian motion and Schmidt number. The model's predictions show strong agreement with existing literature, confirming its validity. Applications of this bioconvective nanofluid model span microfluidics mixing, bioreactors, wastewater treatment, and thermal regulation in biomedical and energy-related systems. The integration of bioconvection into nanofluid technologies presents a promising strategy for optimizing heat and mass transfer across various industrial and environmental domains.