Purpose

The purpose of this study is to investigate the interaction between magnetotactic bacteria and Fe₃O₄–water nanofluid (NF) in a wavy enclosure in the presence of 2D natural convection flow.

Design/methodology/approach

Uniform magnetic field (MF), Brownian and thermophoresis effects are also contemplated. The dimensionless, time-dependent equations are governed by stream function, vorticity, energy, nanoparticle concentration and number of bacteria. Radial basis function-based finite difference method for the space derivatives and the second-order backward differentiation formula for the time derivatives are performed. Numerical outputs in view of isolines as well as average Nusselt number, average Sherwood number and flux density of microorganisms are presented.

Findings

Convective mass transfer rises if any of Lewis number, Peclet number, Rayleigh number, bioconvection Rayleigh number and Brownian motion parameter increases, and the flux density of microorganisms is an increasing function of Rayleigh number, bioconvection Rayleigh number, Peclet number, Brownian and thermophoresis parameters. The rise in buoyancy ratio parameter between 0.1 and 1 and the rise in Hartmann number between 0 and 50 reduce all outputs average Nusselt, average Sherwood numbers and flux density of microorganisms.

Research limitations/implications

This study implies the importance of the presence of magnetotactic bacteria and magnetite nanoparticles inside a host fluid in view of heat transfer and fluid flow. The limitation is to check the efficiency on numerical aspect. Experimental observations would be more effective.

Practical implications

In practical point of view, in a heat transfer and fluid flow system involving magnetite nanoparticles, the inclusion of magnetotactic bacteria and MF effect provide control over fluid flow and heat transfer.

Social implications

This is a scientific study. However, this idea may be extended to sustainable energy or biofuel studies, too. This means that a better world may create better social environment between people.

Originality/value

The presence of magnetotactic bacteria inside a Fe₃O₄–water NF under the effect of a MF is a good controller on fluid flow and heat transfer. Since the magnetotactic bacteria is fed by nanoparticles Fe₃O₄ which has strong magnetic property, varying nanoparticle concentration and Brownian and thermophoresis effects are first considered.

中文翻译：

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波状壁腔中的趋磁细菌和 Fe3O4-水

目的

本研究的目的是研究在二维自然对流存在的情况下，在波浪状外壳中趋磁细菌与 Fe ₃ O _{4 -水纳米流体 (NF) 之间的相互作用。}

设计/方法论/途径

还考虑了均匀磁场(MF)、布朗效应和热泳效应。无量纲、与时间相关的方程由流函数、涡度、能量、纳米颗粒浓度和细菌数量控制。对空间导数采用基于径向基函数的有限差分法，对时间导数采用二阶后向微分公式。给出了等值线的数值输出以及微生物的平均努塞尔数、平均舍伍德数和通量密度。

发现

如果路易斯数、佩克莱特数、瑞利数、生物对流瑞利数和布朗运动参数中的任何一个增加，对流传质就会增加，并且微生物的通量密度是瑞利数、生物对流瑞利数、佩克莱特数、布朗和热泳参数的增函数。浮力比参数在0.1和1之间的增加以及哈特曼数在0和50之间的增加降低了所有输出的平均努塞尔数、平均舍伍德数和微生物的通量密度。

研究局限性/影响

这项研究暗示了宿主流体内存在的趋磁细菌和磁铁矿纳米粒子对于传热和流体流动的重要性。限制是检查数值方面的效率。实验观察会更有效。

实际影响

从实践的角度来看，在涉及磁铁矿纳米粒子的传热和流体流动系统中，趋磁细菌的包含和MF效应提供了对流体流动和传热的控制。

社会影响

这是一项科学研究。然而，这个想法也可以扩展到可持续能源或生物燃料研究。这意味着一个更美好的世界可以为人与人之间创造更好的社会环境。

原创性/价值

_{在 MF 的作用下，Fe 3} O ₄ -水 NF中存在趋磁细菌，是流体流动和传热的良好控制器。由于趋磁细菌以具有强磁性的纳米颗粒Fe ₃ O ₄为食，因此首先考虑变化的纳米颗粒浓度以及布朗效应和热泳效应。