Purpose

The purpose of this study is to address magnetohydrodynamic (MHD) bioconvection caused by the swimming of oxytactic microorganisms in a linearly heated square cavity filled with porous media and Cu–water nanofluid. The effects of different multiphysical aspects are demonstrated using local distributions as well as global quantities for fluid flow, temperature, oxygen concentration and microorganisms population.

Design/methodology/approach

The coupled transport equations are converted into the nondimensional partial differential equations, which are solved numerically using a finite volume-based computing code. The flow of Cu–water nanofluid through the pores of porous media is formulated following the Brinkman–Forchheimer–Darcy model. The swimming of oxytactic microorganisms is handled following a continuum model.

Findings

The analysis of transport phenomena of bioconvection is performed in a linearly heated porous enclosure containing Cu–water nanofluid and oxytactic microorganisms under the influence of magnetic fields. The application of such a system could have potential impacts in diverse fields of engineering and science. The results show that the flow and temperature distribution along with the isoconcentrations of oxygen and microorganisms is markedly affected by the involved governing parameters.

Research limitations/implications

Similar study of bioconvection could be extended further considering thermal radiation, chemical attraction, gravity and light.

Practical implications

The outcomes of this investigation could be used in diverse fields of multiphysical applications, such as in food industries, chemical processing equipment, fuel cell technology and enhanced oil recovery.

Originality/value

The insight of the linear heating profile reveals a special attribute of simultaneous heating and cooling zones along the heated side. With such an interesting feature, the MHD bioconvection of oxytactic microorganisms in nanofluid-filled porous substance is not reported so far.

中文翻译：

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含铜水纳米流体饱和多孔介质中催产微生物的磁流体动力学生物对流

目的

本研究的目的是解决由催产微生物在充满多孔介质和铜水纳米流体的线性加热方腔中游动引起的磁流体动力学 (MHD) 生物对流。使用局部分布以及流体流动、温度、氧气浓度和微生物种群的全局量来证明不同多物理方面的影响。

设计/方法/方法

耦合输运方程被转换为无量纲偏微分方程，这些方程使用基于有限体积的计算代码进行数值求解。Cu-水纳米流体通过多孔介质孔隙的流动遵循 Brinkman-Forchheimer-Darcy 模型。按照连续模型处理催产微生物的游动。

发现

在磁场影响下，在含有铜水纳米流体和催产微生物的线性加热多孔外壳中进行生物对流传输现象的分析。这种系统的应用可能会对工程和科学的各个领域产生潜在影响。结果表明，流量和温度分布以及氧气和微生物的等浓度受所涉及的控制参数的显着影响。

研究限制/影响

考虑到热辐射、化学引力、重力和光，可以进一步扩展对生物对流的类似研究。

实际影响

这项调查的结果可用于多物理应用的不同领域，例如食品工业、化学加工设备、燃料电池技术和提高石油采收率。

原创性/价值

对线性加热曲线的洞察揭示了沿加热侧同时加热和冷却区域的特殊属性。由于具有如此有趣的特征，纳米流体填充的多孔物质中催产微生物的 MHD 生物对流迄今尚未见报道。