Abstract The heat transfer and friction factor of a new kind of nanodiamond-nickel (ND-Ni) hybrid nanofluids flow in a tube with and without longitudinal strip inserts were studied experimentally. The hybrid ND-Ni nanoparticles were synthesized using in-situ and chemical coprecipitation method and characterized with different techniques. The bulk quantity of hybrid ND-Ni nanofluids were prepared and used for heat transfer and friction analysis. The experiments were conducted in the Reynolds number range from 3000 to 22,000, for the volume concentrations of 0.1% and 0.3%, and for different aspect ratios (AR = 1, 2 and 4) of the longitudinal strip inserts. The Nusselt number is enhanced by 35.43% (without insert) and further enhanced by 93.30% with longitudinal strip insert (AR = 1) for 0.3% volume concentration of nanofluid and at Reynolds number of 22,000 compared to water data. The friction factor penalty of 1.12-times without inserts and further penalty of 1.248-times with longitudinal strip insert (AR = 1) at 0.3% volume concentration of nanofluid and at Reynolds number of 22,000 compared to water data. The obtained experimental Nusselt number of hybrid nanofluids was compared with that of other kind of hybrid nanofluids available in the literature. The Nusselt number and friction factor correlations were developed based on the experimental data.

中文翻译：

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纳米金刚石-镍混合纳米流体在具有纵向条形插入件的管中流动的传热和摩擦系数

摘要 通过实验研究了一种新型纳米金刚石-镍（ND-Ni）混合纳米流体在带有和不带有纵向条形插入件的管中流动的传热和摩擦系数。使用原位和化学共沉淀方法合成了杂化 ND-Ni 纳米粒子，并用不同的技术进行表征。大量的混合 ND-Ni 纳米流体被制备并用于传热和摩擦分析。实验是在 3000 到 22,000 的雷诺数范围内进行的，体积浓度为 0.1% 和 0.3%，并且纵向条插入的不同纵横比（AR = 1、2 和 4）。Nusselt 数增加了 35.43%（无插入），并进一步增加了 93.30%，使用纵向条插入（AR = 1）为 0。与水数据相比，纳米流体体积浓度为 3%，雷诺数为 22,000。与水数据相比，在 0.3% 的纳米流体体积浓度和 22,000 的雷诺数下，没有插入物的摩擦系数损失为 1.12 倍，使用纵向条状插入物（AR = 1）进一步损失为 1.248 倍。将获得的混合纳米流体的实验努塞尔数与文献中可用的其他类型的混合纳米流体进行比较。Nusselt 数和摩擦系数的相关性是基于实验数据开发的。将获得的混合纳米流体的实验努塞尔数与文献中可用的其他类型的混合纳米流体进行比较。Nusselt 数和摩擦系数的相关性是基于实验数据开发的。将获得的混合纳米流体的实验努塞尔数与文献中可用的其他类型的混合纳米流体进行比较。Nusselt 数和摩擦系数的相关性是基于实验数据开发的。