The Nanoscale Boundary Layer and Nanoscale Vortex Core
The nanoscale boundary layer and nanoscale vortex core refer to regions of intense vorticity, or shear, within 100 nanometers of a solid surface or vortex center, respectively. In the shear layers at fluid/wall interfaces and in vortex cores, it is shown, based on molecular kinetic theory and thermodynamics, that the macroscopic(solid body) rotation must be accompanied by internal rotation of the molecules. It is also shown that in the presence of rotating molecules with matching macroscopic, or local, rotation, electric polarization of the internal molecular rotations about the local rotation axis—the Barnett effect—occurs. In such a spin aligned system, changes in the physical properties of the fluid result—electric polarization; heat conduction and optical properties are taken as examples. Moreover, in the presence of solid body rotation while there is vorticity, there is no shear viscosity. References to published experimental data are given which support the changes in heat conduction and optical properties. Such major changes in the physical properties of fluids is a feature of nanoscale physics. For example, thermal energy transport is by wave motion rather than by molecular collisions. There is a distinctive phase transition at the nanoscale from the macroscopic scale at the upper limit to the molecular scale at the lower limit. Calculations are done for the expected magnetic polarization in the shear, or boundary, layer on swept wings, using published data for vortex physical properties for a delta wing. Expressions for the interactive force, or pressure, between an external electric field and this vortex magnetic dipole array are derived and calculations performed. It is predicted that for even relatively low electric field strengths, with the appropriate field polarity, the boundary layer would be held down on the wing surface in opposition to maximum separation pressure, thus preventing separation even at high angles of attack. Magnetic polarization due to charge separation also occurs in nanotubes and allows for electrokinetic pumping as an alternate to hydraulic pumping. Recognition of the existence of nanoscale fluid physics affords the possibility of new methods of fluid flow control.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: 2007-09-01
More about this publication?
- Journal of Computational and Theoretical Nanoscience is an international peer-reviewed journal with a wide-ranging coverage, consolidates research activities in all aspects of computational and theoretical nanoscience into a single reference source. This journal offers scientists and engineers peer-reviewed research papers in all aspects of computational and theoretical nanoscience and nanotechnology in chemistry, physics, materials science, engineering and biology to publish original full papers and timely state-of-the-art reviews and short communications encompassing the fundamental and applied research.
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites