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The onset of bio‐thermal convection induced by a combined effect of gyrotactic and oxytactic microorganisms

A.V. Kuznetsov (Mechanical & Aerospace Engineering, North Carolina State University, Raleigh, North Carolina, USA)

International Journal of Numerical Methods for Heat & Fluid Flow

ISSN: 0961-5539

Article publication date: 2 August 2013

188

Abstract

Purpose

The purpose of this paper is to investigate the stability of a suspension containing both gyrotactic and oxytactic microorganisms for the case when the suspension occupies a horizontal layer of finite depth. The lower boundary of the layer is assumed rigid while at the upper boundary both situations of rigid and stress‐free boundary conditions are considered.

Design/methodology/approach

Linear instability analysis is utilized, and the obtained eigenvalue problem is solved analytically using a one‐term Galerkin method.

Findings

The obtained eigenvalue equation relates three Rayleigh numbers, the traditional thermal Rayleigh number and two bioconvection Rayleigh numbers, for gyrotactic and oxytactic microorganisms.

Research limitations/implications

Only the case of non‐oscillatory instability (which always occurs when heating from the bottom is considered) is analyzed. Further experimental research is needed to elucidate possible interaction between gyrotactic and oxytactic microorganisms. The developed theory is applicable only for dilute suspensions.

Originality/value

This paper extends the traditional theory of bio‐thermal convection to the case when the suspension contains two types of motile microorganisms exhibiting different behaviors.

Keywords

Citation

Kuznetsov, A.V. (2013), "The onset of bio‐thermal convection induced by a combined effect of gyrotactic and oxytactic microorganisms", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 23 No. 6, pp. 979-1000. https://doi.org/10.1108/HFF-09-2011-0178

Publisher

:

Emerald Group Publishing Limited

Copyright © 2013, Emerald Group Publishing Limited

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