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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Effect of Wall Structures on Nano-Channel Flows

Get access (open in a dialog) DOI: 10.1615/IHTC15.nms.009130
pages 5685-5693

Sinopsis

The effect of wall molecule structure on near-wall flow behavior is investigated in nano-channel flows by performing non-equilibrium molecular dynamics simulations. A monoatomic molecule is presumed as the fluid and the channel wall is consisted by identical molecular. The wall molecular structures are arranged at facecentered cubic lattice with different orientations, diamond, and graphite molecular positions to pronounce the effect of the wall molecule structure on the flow especially near the wall. The targeted Knudsen number (Kn) is in the range from 0.02 to 2.0. It is found that a hook-like velocity profile is observed in the vicinity of the wall at some wall molecular structures, which becomes remarkable at higher Kn. The elevation at minimum velocity is found to correspond to the maxima of the molecular number density, of which magnitude is also affected by the surface wall structure. It is thus understood that the wall molecular structure is related to the attracting force of the fluid molecule near the wall, which results in the locally high concentration of fluid molecule with hook-like velocity profile. This implies that the flow near the wall cannot be fully understood only by the Kn.