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Thermo-bioconvection of oxytactic microorganisms in porous media in the presence of magnetic field

Nirmalendu Biswas (Department of Power Engineering, Jadavpur University, Kolkata, India)
Aparesh Datta (Department of Mechanical Engineering, National Institute of Technology-Durgapur, Durgapur, India)
Nirmal K. Manna (Department of Mechanical Engineering, Jadavpur University, Kolkata, India)
Dipak Kumar Mandal (Department of Mechanical Engineering, College of Engineering and Management, Kolkata, India)
Rama Subba Reddy Gorla (Department of Aeronautics and Astronautics, Air Force Institute of Technology, Dayton, Ohio, USA)

International Journal of Numerical Methods for Heat & Fluid Flow

ISSN: 0961-5539

Article publication date: 23 November 2020

Issue publication date: 3 May 2021




This study aims to explore magnetohydrodynamic (MHD) thermo-bioconvection of oxytactic microorganisms in multi-physical directions addressing thermal gradient, lid motion, porous substance and magnetic field collectively using a typical differentially heated two-sided lid-driven cavity. The consequences of a range of pertinent parameters on the flow structure, temperature, oxygen isoconcentration and microorganisms’ isoconcentration are examined and explained in great detail.


Two-dimensional governing equations in a two-sided lid-driven porous cavity heated differentially and packed with oxytactic microorganisms under the influence of the magnetic field are solved numerically using the finite volume method-based computational fluid dynamics code. The evolved flow physics is analyzed assuming a steady laminar incompressible Newtonian flow within the validity of the Boussinesq approximation. The transport of oxytactic microorganisms is formulated by augmenting the continuum model.


The mechanisms involved with MHD-mixed thermo-bioconvection could have potential benefits for industrial exploitation. The distributions of fluid flow, temperature, oxygen and motile microorganisms are markedly modified with the change of convection regime. Both speed and direction of the translating walls significantly influence the concentration of the motile microorganisms. The concentration of oxygen and motile microorganisms is found to be higher at the upper portion of the cavity. The overall patterns of the fluid flow, temperature and the oxygen and microorganism distributions are markedly affected by the increase of magnetic field strength.

Research limitations/implications

The concept of the present study could be extended to other areas of bioconvection in the presence of gravity, light or chemical attraction.

Practical implications

The findings of the present study could be used to multi-physical applications like biomicrosystems, pollutant dispersion in aquifers, chemical catalytic converters, geothermal energy usage, petroleum oil reservoirs, enhanced oil recovery, fuel cells, thermal energy storage and others.


The MHD-mixed thermo-bioconvection of oxytactic microorganisms is investigated under different parametric conditions. The effect of pertinent parameters on the heat and mass transfers are examined using the Nusselt number and Sherwood number.



The present authors would like to thank anonymous reviewers for their comments and valuable suggestions, which have improved the quality of this manuscript.

Conflict of interest: None declared.


Biswas, N., Datta, A., Manna, N.K., Mandal, D.K. and Gorla, R.S.R. (2021), "Thermo-bioconvection of oxytactic microorganisms in porous media in the presence of magnetic field", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 31 No. 5, pp. 1638-1661.



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