界面层强化纳米流体热导率特性分析

Characteristic analysis of the thermal conductivity of enhanced nanofluidsat the interface

受分子间作用力的影响,纳米颗粒表面附近的液体分子排列比较紧密,形成界面层。为了深入研究界面层对纳米流体热导率的影响,对比分析了考虑界面层效应的纳米流体热导率模型,讨论了界面层热导率、界面层厚度以及纳米颗粒尺寸对纳米流体热导率的影响。研究结果表明,界面层能够提高纳米流体的热导率,并且界面层热导率与厚度是影响纳米流体热导率的重要因素,尤其当纳米颗粒体积分数较高,纳米颗粒尺寸较小时,2种因素的影响更加明显。此外,受界面层厚度的影响,界面层热导率对纳米流体热导率的影响程度随着界面层厚度的增加而升高。

Due to the effects between molecular interactions, the liquid molecules close to a nanoparticle surface can arrange closely together.This compact structure of liquid molecules at the interface is often called interfacial nano-layer.In order to further study the effects of the interfacial nanolayer on the thermal conductivity of nanofluids, dif-ferent thermal conductivity models considering interfacial nanolayer for nanofluids are analyzed contrastively in this paper.Several parameters such as thermal conductivity of interfacial nanolayer, interfacial nanolayer thickness and nanoparticle size are discussed.The results showed that the interfacial nanolayer can improve the thermal conductiv-ity of nanofluids.Based on the investigation, it is also found that the thermal conductivity and thickness of the inter-facial nanolayer are important factors affecting thermal conductivity of nanofluids and the effects are very significant when the nanoparticle volume fraction is larger and nanoparticle size is smaller.Affected by interfacial nanolayer thickness, the effects of the interfacial nanolayer thermal conductivity on the thermal conductivity of nanofluids can be more obvious with the increase of interfacial nanolayer thickness.