Computation of unsteady reactive magnetized bioconvective micropolar nanofluid squeezing flow with Stefan blowing and heat source effects

Bég, O Anwar; Khan, W A; Mojumdar, Shakil; Uddin, M J; Bég, T A

Abstract

Motivated by emerging applications in smart bio-nano-tribology, a mathematical model for the unsteady, magnetohydrodynamic chemically reacting bioconvective micropolar Buongiorno nanofluid squeezing flow between two parallel plates subject to Stefan blowing and heat source effects is developed, and examined. The presence of the gyrotactic bioconvection microorganisms in the nanofluid prevents nanoparticle agglomeration, improves the stability of nanofluids, improves mixing, and encourages the development of a beneficial nanoparticle volume fraction gradient. Suitable coordinate transformations are applied to reduce the fundamental transport equations into similarity equations before solving them numerically with a 4 th-5 th order Runge-Kutta Method within Maple 24 symbolic software. The influences of the controlling parameters on the dimensionless velocity, angular velocity (micro-rotation), temperature, nanoparticle volume fraction (NPVF), density of motile microorganisms, as well as on the physical quantities (shear stress, Nusselt number, nanoparticle Sherwood number, and microorganism density gradient) are investigated and visualized graphically. The computed results for the Nusselt number and NPVF Sherwood numbers are compared with existing results for several limiting cases, and excellent agreement is found. It is shown that skin friction increases with elevation in micro-rotation and blowing parameters, whereas Nusselt number, nanoparticle Sherwood number, and microorganism wall gradient increase with micro-rotation parameters both in the presence and absence of blowing. With increasing squeeze number, angular velocity, temperature, and NPVF increase substantially, whereas the motile microorganism density number weakly increases in the regime. Nusselt number is strongly enhanced with more significant magnetic field parameters, whereas it is reduced with larger values of micro-rotation parameter and squeeze number. The present study is relevant to hybrid magnetic lubrication systems and highlights the benefits of combining magnetic non-Newtonian nanofluids with bioconvection effects for improved thermal management.

• Journal Article Type: Article
• Acceptance Date: May 13, 2025
• Deposit Date: May 15, 2025
• Publicly Available Date: May 19, 2025
• Print ISSN: 2397-7914
• Electronic ISSN: 2397-7922
• Publisher: SAGE Publications
• Peer Reviewed: Peer Reviewed
• Keywords: Squeezing flow; magnetic lubrication; bioconvection; micropolar nanofluid; Stefan blowing; Microorganisms; Maple 24