Severe D-1 directional Fourier truncation of the equations for D-dimensional (D = 2, 3) incompressible flow leads to a small number of coupled PDE's in one space dimension with the same inviscid quadratic invariants as the original set. Numerically generated equilibria for inviscid truncated versions of the reduced systems agree with predicted energy-enstrophy (D = 2) and energy (D = 3) equipartition spectra based on statistical mechanical equilibrium. Viscous calculations for forced and decaying turbulence at high Reynolds number are consistent with k$ sp{-5/3}$ inverse energy and k$ sp{-3}$ direct enstrophy cascading inertial ranges in two dimensions and with a k$ sp{-5/3}$ direct energy cascading inertial range in three dimensions. The power-law behaviour is clear in the two-dimensional system, but less convincing in three dimensions due to the persistence of a shallow spectral range at low wavenumbers. / Dissipation-range intermittency consisting of spatially intermittent vorticity gradients (D = 2) and vorticity (D = 3) is observed. In contrast to full numerical simulations, there is no tendency for isolated coherent structures to emerge in two dimensions. The model consequently mimics some, but not all, of the properties of the full set.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.75855 |
| Date | January 1988 |
| Creators | Bartello, Peter |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Meteorology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000730511, proquestno: AAINL48587, Theses scanned by UMI/ProQuest. |
Page generated in 0.0019 seconds