Suresh S, Venkitaraj K P, Hameed M Shahul, Sarangan J
J Nanosci Nanotechnol. 2014 Mar;14(3):2563-72. doi: 10.1166/jnn.2014.8467.
A study on fully developed turbulent convective heat transfer and pressure drop characteristics of Al2O3-Cu/water hybrid nanofluid flowing through a uniformly heated circular tube is presented in this paper. For this, Al2O3-Cu nanocomposite powder was synthesized in a thermo chemical route using hydrogen reduction technique and dispersed the hybrid nano powder in deionised water to form a stable hybrid nanofluid of 0.1% volume concentration. The prepared powder was characterized by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) to confirm the chemical composition, determine the particle size and study the surface morphology. Stability of the nanofluid was ensured by pH and zeta potential measurements. The average heat transfer enhancement for Al2O3-Cu/water hybrid nanofluid is 8.02% when compared to pure water. The experimental results also showed that 0.1% Al2O3-Cu/water hybrid nanofluids have slightly higher friction factor compared to 0.1% Al2O3/water nanofluid. The empirical correlations proposed for Nusselt number and friction factor were well agreed with the experimental data.
本文介绍了一项关于Al2O3-Cu/水混合纳米流体在均匀加热圆管中充分发展的湍流对流换热和压降特性的研究。为此，采用氢还原技术通过热化学路线合成了Al2O3-Cu纳米复合粉末，并将混合纳米粉末分散在去离子水中，形成体积浓度为0.1%的稳定混合纳米流体。通过X射线衍射（XRD）和扫描电子显微镜（SEM）对制备的粉末进行表征，以确认化学成分、确定粒径并研究表面形态。通过pH值和zeta电位测量确保纳米流体的稳定性。与纯水相比，Al2O3-Cu/水混合纳米流体的平均传热增强率为8.02%。实验结果还表明，0.1%的Al2O3-Cu/水混合纳米流体的摩擦系数比0.1%的Al2O3/水纳米流体略高。所提出的努塞尔数和摩擦系数的经验关联式与实验数据吻合良好。
