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Persistent URL http://purl.org/net/epubs/work/29571
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Record Id 29571
Title A numerical study of low Reynolds number slip flow in the hydrodynamic development region of circular and parallel plate ducts
Abstract One of the major difficulties in trying to predict gaseous transport in micron-sized devices can be attributed to the fact that the continuum flow assumption implemented in the Navier-Stokes equations breaks down when the mean free path of the molecules is comparable to the characteristic dimensions of the flow domain. Under these conditions, the momentum transfer starts to be affected by the discrete molecular composition of the gas and a variety of non-continuum or rarefaction effects are likely to be exhibited. Velocity profiles, volume rates of flow and boundary wall shear stresses are all influenced by the non-continuum regime. In addition, the length of the hydrodynamic development region at the entrance to a channel may also be affected. The present investigation examines the effects of the Reynolds number and the Knudsen number on the hydrodynamic development lengths in circular and parallel plate ducts. The study was conducted using THOR-2D - a two-dimensional finite-volume Navier-Stokes solver developed by the Computational Engineering Group at CLRC Daresbury Laboratory. The solver was specifically adapted for the simulation of non-continuum flows by the inclusion of appropriate tangential slip-velocity boundary conditions at the solid perimeter walls. Results from the present study suggest that hydrodynamic development lengths for the circular pipe are only marginally affected by Knudsen number. However, in the case of the parallel plate geometry, entrance development lengths in the slip-flow regime are approximately 25% longer than the corresponding continuum solution.
Organisation CCLRC , CSE , CSE-CEG
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Language English (EN)
Type Details URI(s) Local file(s) Year
Report DL Technical Reports DL-TR-2000-002. 2000. dltr-2000002.pdf 2000