论文标题
界面耐药性和纳米层对Al2O3-CO2纳米流体的热导率的影响：一种分子动力学方法
Thermal interfacial resistance and nanolayer effect on the thermal conductivity of Al2O3-CO2 nanofluid: A Molecular Dynamics approach
论文作者
论文摘要
已知纳米流体具有显着不同的热性能 相对于相应的常规流体。传热 固体界面会影响纳米流体的热特性。当前的工作有助于了解两种纳米级现象的作用，即纳米颗粒周围的流体层（纳米层）的顺序以及固体富型界面对Al2O3 -CO2二氧化碳导热率增强的界面中的热电阻。在这项研究中，已经使用了分子动力学（MD）模拟来研究通过瞬态非平衡热技术和在气态和超临界相中的Al2O3纳米颗粒（NP）和周围的CO2分子之间形成的纳米层。纳米颗粒直径（DNP）在2至5 nm之间变化，以研究纳米流体的热界面电阻（TIR）和导热率的尺寸影响，结果表明，在这两个相中，较大直径的TIR相对较高。对表面润湿性和温度对TIR的影响的研究表明，在气态和超临界纳米流体中，电阻随相互作用强度和温度的增加而降低，但在较高温度下完全独立。纳米层和纳米颗粒周围的单层的密度分布研究表明，后者以较小的直径有序，热电阻较少。但是，纳米层的研究表明，较大直径的纳米颗粒更适合冷却/加热目的，因为较大直径的系统具有较高的导热率。结果表明，纳米层在确定纳米流体的有效导热率中起着重要作用，而与纳米层相比，TIR的影响似乎可以忽略不计。
Nanofluids are known to have significantly different thermal properties relative to the corresponding conventional fluids. Heat transfer at the solid-fluid interface affects the thermal properties of nanofluids. The current work helps in understanding the role of two nanoscale phenomena, namely ordering of fluid layer around the nanoparticle (nanolayer) and thermal resistance at the interface of solid-fluid in the enhancement of thermal conductivity of Al2O3 - CO2 nanofluid. In this study, molecular dynamics (MD) simulations have been used to study the thermal interfacial resistance by transient non-equilibrium heat technique and nanolayer formed between Al2O3 nanoparticle (np) and surrounded CO2 molecules in the gaseous and supercritical phase. The nanoparticle diameter (dNP) is varied between 2 and 5 nm to investigate the size effect on thermal interfacial resistance (TIR) and thermal conductivity of nanofluid and the results indicate that the TIR for larger diameters is relatively high in both the phases. The study of the effect of surface wettability and temperature on TIR reveals that the resistance decreases with increase in interaction strength and temperature, but is entirely independent at higher temperatures, in both gaseous and supercritical nanofluid. A density distribution study of the nanolayer and the monolayer around the nanoparticle revealed that the latter is more ordered in smaller diameter with less thermal resistance. However, nanolayer study reveals that the nanoparticle with bigger diameters are more suitable for the cooling/heating purpose, as the system with larger diameters has higher thermal conductivity. Results show that the nanolayer plays a significant role in determining the effective thermal conductivity of the nanofluid, while the influence of TIR appears negligible compared to the nanolayer.
