الفهرس | Only 14 pages are availabe for public view |
Abstract An investigation on the breakdown of the Navier-Stokes equations (NSE) for nano scale flow between two parallel planner plates is presented under different boundary conditions. Molecular dynamics (MD) simulations of force-driven liquid argon flow are performed to highlight the effect of boundary conditions and fluid inhomogeneity properties on violation of NSE. In the present study, the effect of channel heights and different values of wall shear stress are considered for the same wall structure and wall-fluid interaction (WFI). The heat generated in a force-driven flow is removed by thermal interacting wall model for nearly constant mean fluid temperature through adjusting the wall temperature. The results of MD simulations showed a classification of controlled and uncontrolled temperature flow mode (CTFM, UTFM) related to wall shear stress limit (WSSL). The results indicated the effect of wall shear stress on the trend of temperature profiles and depletion layer thickness for channel heights. However, the change of effective channel height and average density were attributed to decrease the depletion layer thickness. It is noticed the effect of density and temperature on changing the fluid pressure in case of CTFM and UTFM. While the supercritical state of fluid beyond WSSL was attributed to significant effect of pressure and temperature. The results showed relevant change of fluid inhomogeneity near wall and slip length related to wall shear stress and channel heights. It was found that the breakdown of NSE can be highlighted through error percentage of mass flow rate. Significant differences of NSE violation compared with MD simulation results were noticeable, while these differences were irrelevant for insignificant effect of fluid inhomogeneity and nearly zero slip length. |