Investigating the effect of shape, size and surface wettability of a nanochannel on fluid thermal conductivity using molecular dynamics simulation

The main goal and innovation of this study is to analyze the effects of the configuration of the walls and their orientation (parallel or perpendicular to the flow direction) on the behavior of the thermal properties of the fluid. So, in this paper, the effects of shape, size, and surfaces wettability of nanochannel with a focus on walls configuration on the thermal conductivity of fluid are investigated. Equilibrium molecular dynamics simulation is used for this purpose. Two parallel plates, a square cross-sectional nanochannel, and a rectangular cross-sectional nanochannel are examined as three different nanochannel shapes. According to results, the shape and size of the nanochannel are a significant factor in thermal conductivity, which is caused by the effect of walls on the mobility and arrangement of fluid atoms in the nanochannel. The walls have a negative effect in terms of the mobility of atoms, but in terms of the arrangement of the atoms, they have opposite effects depending on their orientation (perpendicular or parallel to the desired direction). As a result, in a same channel height, square channels have a higher thermal conductivity than slit channels, since the side walls affect thermal conductivity positively. The results also indicate that with the increase in the wettability of the nanochannel surfaces, the thermal conductivity decreases. In this case, fluid thermal conductivity is more affected by the walls.

کلیدواژه ها:

thermal conductivity ، nanochannel shape ، wall effect ، surface wettability ، equilibrium molecular dynamics (EMD)