Pal Rajinder
Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
Nanomaterials (Basel). 2014 Oct 13;4(4):844-855. doi: 10.3390/nano4040844.
Nanofluids are becoming increasingly popular as heat transfer fluids in a variety of industrial applications, due to their enhanced heat transfer characteristics. The thermal conductivity of nanofluids is usually found to be much larger than that predicted from the classical models, such as the Maxwell model. The key mechanism of enhancement of thermal conductivity of dilute nanofluids is the solvation of nanoparticles with a layer of matrix liquid. As of now, little is known quantitatively about the thermal conductivity of the interfacial layers surrounding the nanoparticles. In this article, a novel method is presented to determine the thermal conductivity of the interfacial layers of the nanoparticles. The proposed method allows the estimation of the thermal conductivity of interfacial layers based on the combined measurements of the intrinsic viscosity and intrinsic thermal conductivity of a bulk nanofluid. From the measured intrinsic viscosity of the nanofluid, the thickness of the interfacial layer is estimated. Using the known interfacial layer thickness along with the measured intrinsic thermal conductivity of the nanofluid, the thermal conductivity of the interfacial layer is estimated. The proposed method is validated by simulation and experimental results.
由于其增强的传热特性，纳米流体作为传热流体在各种工业应用中越来越受欢迎。通常发现纳米流体的热导率远大于经典模型（如麦克斯韦模型）预测的值。稀纳米流体热导率增强的关键机制是纳米颗粒被一层基体液体溶剂化。到目前为止，关于纳米颗粒周围界面层的热导率，定量了解很少。在本文中，提出了一种测定纳米颗粒界面层热导率的新方法。所提出的方法允许基于对本体纳米流体的特性粘度和本征热导率的联合测量来估计界面层的热导率。根据测得的纳米流体特性粘度，估计界面层的厚度。利用已知的界面层厚度以及测得的纳米流体本征热导率，估计界面层的热导率。通过模拟和实验结果验证了所提出的方法。
