Thermal Conductivity Mechanism of Oil-Cooled Copper Surfaces Based on the Molecular Dynamics Approach

Since oil has great potential in the surface heat dissipation system of CT tubes. However, the interfacial thermal resistance between copper and oil and the thermal conductivity of oil itself severely limit the heat dissipation efficiency. In this article, the effect of flow rate on the interfacial heat transport problem on the surface of an oil-cooled CT tube and the effect of carbon nanotubes on the thermal conductivity of oil are investigated using molecular dynamics methods, respectively. The results show that the interfacial thermal resistance decreases by 2.56, 11.31, 26.38, and 37.15% sequentially when the oil flow velocity increases from 0 to 4 m/s. When the velocity increased to 5 m/s, it decreased by 20.73%, and the interfacial thermal resistance increased by 21.13% when the cu moving velocity was at 1 m/s. The interfacial thermal resistance decreased significantly with the increase in velocity, with the maximum occurring at 4 m/s at 18.44%. When the velocity increased to 5 m/s, it decreased by 10.01%. The thermal conductivity of the oil was significantly improved by the carbon nanotubes modified by functional groups, and the thermal conductivity increased by 14.71, 42.57, and 101.98%, respectively; in addition, the carbon nanotubes modified by functional groups were more evenly distributed inside the oil. The results of this study provide important theoretical guidance for liquid cooling equipment and the preparation of high thermal conductivity fluid composites.