Magnetohydrodynamic mixed bioconvection of oxytactic microorganisms in a nanofluid-saturated porous cavity heated with a bell-shaped curved bottom

Abstract

Purpose This study aims to investigate thermo-bioconvection of oxytactic microorganisms occurring in a nanofluid-saturated porous lid-driven cavity in the presence of the magnetic field. The heating is provided through a bell-shaped curved bottom wall heated isothermally. The effects of the peak height of the curved bottom wall, bioconvection Rayleigh number (Rb), Darcy number (Da), Hartmann number (Ha), Peclet number (Pe), Lewis number (Le) and Grashof number (Gr) on the flow structure, temperature and the iso-concentrations of oxygen and microorganisms are examined and explained systematically. The local and global, characteristics of heat transfer and oxygen concentration, are estimated through the Nusselt number (Nu) and Sherwood number (Sh), respectively. Design/methodology/approach The governing equations of continuity, momentum, energy and additionally consisting of species transport equations for oxygen concentration and population density of microorganisms, are discretized by the finite volume method. The evolved linearized algebraic equations are solved iteratively through the alternate direction implicit scheme and the tri-diagonal matrix algorithm. The computation domain has meshed in non-uniform staggered grids. The entire computations are carried out through an in-house developed code written in FORTRAN following the SIMPLE algorithm. The third-order upwind and second-order central difference schemes are used for handling the advection and diffusion terms, respectively. The convergence criterion for the iterative process of achieving the final solution is set as 10–8 and 10–10, respectively, for the maximum residuals and the mass defect. Findings The results show that the flow and temperature distribution along with the iso-concentrations of oxygen and microorganisms are markedly affected by the curvature of the bottom wall. A secondary circulation is developed in the cavity that changes the flow physics significantly. The Nu increases with the peak height of the curved bottom wall and Da; however, it decreases with Ha and Rb. The Sh increases with Da but decreases with Ha and the peak height of the curved wall. Research limitations/implications A similar study of bioconvection could be extended further considering thermal radiation, chemical attraction, gravity, light, etc. Practical implications The outcomes of this investigation could be used in diverse fields of multi-physical applications such as in food industries, chemical processing equipment, fuel cell technology and enhanced oil recovery. Originality/value The insights of bioconvection of oxytactic microorganisms using a curved bottom surface along with other physical issues such as nanofluid, porous substance and magnetic field are addressed systematically and thoroughly.

Hybrid nanofluid magnetohydrodynamic mixed convection in a novel W-shaped porous system

“…The Hall effect and Joule heating are also supposed to be insignificant (Maxwell, 1904) along with the negligible contributions of viscous dissipation and radiation effects (Nield and Bejan, 2013; Manna et al , 2021b). With the aforesaid assumptions, the dimensional and dimensionless transport equations are derived (Massoudi et al , 2020; Biswas et al , 2021f; Sarkar, 2021; Al-Farhany, 2021b; Biswas et al , 2021c) and given below.…”

Thermal radiation impact on heat and mass transfer analysis of nanofluids inside a cavity with gyrotactic microorganisms

“…Jamuna and Balla (2021) deliberated the influence of heat absorption/generation, thermophoresis and Brownian motion on isotherms, isoconcentrations of microorganisms and flow line fields of Buongiorno's type nanofluid within a square porous cavity. Biswas et al (2021) perceived marginal augmentation in the nondimensional rate of heat transport with growing values HFF 33,12 of magnetic field parameter in their work on nanofluid isotherms and isoconcentrations of microorganism characteristics inside a closed cavity pondered with gyrotactic microorganisms. Recently, many authors (Shekar and Kishan, 2015;Chamkha et al, 2018;Dogonchi et al, 2019;Tayebi and Chamkha, 2020;Seyyedi et al, 2020;Tayebi et al, 2021aTayebi et al, , 2021bTayebi et al, , 2021cKrishna et al, 2021;Zidan et al, 2022;Nayak et al, 2022;Tayebi et al, 2022;Tayebi et al, 2023;Meenakshi et al, 2023;Balla et al, 2023) have presented mass and heat transport of various nanoliquids over dissimilar geometries.…”

Impacts of heater-cooler position and Lorentz force on heat transfer and entropy generation of hybrid nanofluid convection in quarter-circular cavity

“…In the background of relatively few pioneering works (Incropera, 1988; Biswas et al , 2015; Biswas et al , 2017; Das and Basak, 2017; Lukose and Basak, 2021; Hamzah et al , 2021), most of the studies address complex phenomena (Biswas et al , 2016a; Jalili et al , 2019; Sarkar et al , 2021; Mondal et al , 2022) involving multiple physics like buoyancy, nanofluid (Rahimi et al , 2019; Ghalambaz et al , 2020; Dutta et al , 2021; Dogonchi et al , 2018; Jalili et al , 2022a), hybrid nanofluid (Sarkar et al , 2015; Ghalambaz et al , 2019; Ali, 2020; Biswas et al , 2021a, 2021b; Manna and Biswas, 2021; Jalili et al , 2022b), magnetic field (Kabeel et al , 2015; Manna et al , 2021a; Giwa et al , 2021; Jalili et al , 2021; Jalili et al , 2022d), porous medium (Comini et al , 1974; Bejan et al , 2004; Biswas et al , 2017; Debayan and Basak, 2017; Manna et al , 2021b; Jalili et al , 2022c), microorganisms (Biswas et al , 2021c, 2021d, 2021e), etc. The studies are found to exist in simple (Lewis, 1987; Biswas et al , 2016a; Manna et al , 2019) to complex geometries (Mandal et al , 2022; Saha et al , 2022a, 2022b; Hussain and Oztop, 2021; Biswas et al , 2021d; Al-Farhany et al , 2021; Bhatti et al , 2021) without or with embedded obstructions (Biswas et al , 2021e; Das, and Basak, 2017; Hussain and Oztop, 2021; Mallick et al , 2021; Sivaraja and Sheremet, 2017).…”