Purpose

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.

Design/methodology/approach

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.

Findings

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.

Originality/value

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.

中文翻译：

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磁场作用下多孔介质中氧化型微生物的热生物对流

目的

这项研究的目的是使用典型的差温加热式双面盖驱动腔体，从多个物理方向探讨含氧微生物的磁流体动力学（MHD）热生物对流，以解决热梯度，盖运动，多孔物质和磁场。研究并详细解释了一系列相关参数对流动结构，温度，氧等浓度和微生物等浓度的影响。

设计/方法/方法

利用基于有限体积法的计算流体力学代码，数值求解了两面盖驱动多孔腔中的二维控制方程，该方程在磁场的影响下被不同程度地加热并充满了趋氧性微生物。在Boussinesq逼近的有效期内，假设存在稳定的层状不可压缩牛顿流，则对演化的流物理学进行了分析。氧合微生物的运输是通过扩展连续模型来制定的。

发现

MHD混合热生物对流涉及的机制可能对工业开发具有潜在的好处。随着对流方式的变化，流体流量，温度，氧气和运动微生物的分布显着改变。平移壁的速度和方向都显着影响运动微生物的浓度。发现氧和运动性微生物的浓度在空腔的上部较高。磁场强度的增加显着影响了流体流动，温度以及氧气和微生物分布的总体模式。

研究局限/意义

在重力，光或化学吸引作用下，本研究的概念可以扩展到生物对流的其他领域。

实际影响

本研究的发现可用于多种物理应用，例如生物微系统，含水层中的污染物扩散，化学催化转化器，地热能利用，石油储层，增强的采油率，燃料电池，热能存储等。

创意/价值

在不同参数条件下研究了混合MHD的氧合微生物的热生物对流。使用Nusselt数和Sherwood数检查相关参数对传热和传质的影响。