A Molecular Dynamics Study on Effects of Nanostructural Clearances on Thermal Resistance at an Interface Between Liquid and Solid

The classical molecular dynamics simulation was conducted in order to clarify the effects of the surface structural clearances in nanometer scale on thermal resistance at a liquid-solid interface as well as static and dynamic behaviours of fluid molecules in the vicinity of the surface. A liquid molecular region confined between the solid walls, of which the interparticle potential was Lennard-Jones type, was employed as a calculation system. The thermal resistance between the liquid molecular region and the solid walls with nanostructures was calculated by the heat flux and the temperature jump obtained in the molecular dynamics simulations. With changing the surface structural clearances from 0 to 2.81 nm the thermal resistance between the liquid molecular region and the solid walls with nanostructures once decreased and became the minimum value when the structural clearances were about 0.7 nm. Surface area in molecular scale and fluid density at the interface were dependent on the surface structural clearances and the thermal resistance index calculated by the relative surface area in molecular scale and the relative fluid density at the interface could predict thermal resistance change depending on the nanostructural clearances. Surface nanostructural clearances affected the fluid molecular motions along the heat transfer direction only when the molecular velocity was averaged over a specific characteristic time. Surface nanostructural clearances affected the diffusion behaviours of fluid molecules in the vicinity of the surface too.