This paper exhibits the oscillatory characteristics of a free convective flow of nanofluids in horizontal concentric annuli of pilot dimensions to provide a mechanical solution against their particles settling which occurs by aggregation. These nanofluids are generated according to each class of particles that may exist with four types of industrial base liquids. Koo–Kleinstreuer semi-empirical models are used to generate databases of ideal suspended particles with Brownian motion. Meanwhile, Maxwell–Bruggeman and Kreiger–Dougherty semi-empirical models are used to incorporate the aggregation mechanism. A hybrid lattice Boltzmann/finite-difference approach is adopted to provide the space-time solutions. The accuracy of this numerical tool is inspected by providing over nine validations based on literature data. Hence, an improved flow pattern chart is accomplished to expand the open literature, depending on the flow nature of the base liquids in the annuli. Next, the oscillatory nature is fully revealed for each nanofluid processed. Following the frontiers toward the non-settling of aggregates, three main regimes are identified depending on the annulus size and the combination between ideal and aggregate mechanisms. Owing to this, a new settling chart is established to emerge the sheer limit of the annulus size for a non-settling process.

中文翻译：

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圆柱环中Koo-Kleinstreuer和聚集的纳米流体的振荡流动：寻求一种解决纳米流体不稳定性的创新解决方案

本文展示了纳米流体在对中尺寸的水平同心环空中的自由对流流动的振荡特性，从而提供了一种针对聚集引起的颗粒沉降的机械解决方案。这些纳米流体是根据每种类别的颗粒生成的，这些颗粒可能与四种类型的工业基础液体一起存在。Koo–Kleinstreuer半经验模型用于生成具有布朗运动的理想悬浮粒子数据库。同时，Maxwell-Bruggeman和Kreiger-Dougherty半经验模型用于合并聚集机制。采用混合格子玻尔兹曼/有限差分方法来提供时空解。通过基于文献数据提供九种以上的验证，可以检查此数字工具的准确性。因此，根据环空中基础液体的流动特性，完成了改进的流图以扩展开放文献。接下来，对于每个处理的纳米流体，其振荡性质都得到了充分揭示。遵循聚集体不沉降的前沿，根据环的大小以及理想与聚集体机制的组合，确定了三个主要机制。因此，建立了一个新的沉降图，以显示非沉降过程的环形空间的绝对极限。根据环形空间的大小以及理想与聚集机制之间的组合，可以确定三种主要状态。因此，建立了一个新的沉降图，以显示非沉降过程中环空尺寸的绝对极限。根据环形空间的大小以及理想与聚集机制之间的组合，可以确定三种主要状态。因此，建立了一个新的沉降图，以显示非沉降过程的环形空间的绝对极限。