Non-white noise and a multiple-rate Markovian closure theory for turbulence
| dc.creator | Hammett, Gregory W. | |
| dc.creator | Bowman, John C. | |
| dc.date | 2002-03-11 | |
| dc.date.accessioned | 2026-07-07T05:47:10Z | |
| dc.date.available | 2026-07-07T05:47:10Z | |
| dc.description | Markovian models of turbulence can be derived from the renormalized statistical closure equations of the direct-interaction approximation (DIA). Various simplifications are often introduced, including an assumption that the two-time correlation function is proportional to the renormalized infinitesimal propagator (Green's function), i.e. the decorrelation rate for fluctuations is equal to the decay rate for perturbations. While this is a rigorous result of the fluctuation--dissipation theorem for thermal equilibrium, it does not necessarily apply to all types of turbulence. Building on previous work on realizable Markovian closures, we explore a way to allow the decorrelation and decay rates to differ (which in some cases affords a more accurate treatment of effects such as non-white noise), while retaining the computational advantages of a Markovian approximation. Some Markovian approximations differ only in the initial transient phase, but the multiple-rate Markovian closure (MRMC) presented here could modify the steady-state spectra as well. Markovian models can be used directly in studying turbulence in a wide range of physical problems (including zonal flows, of recent interest in plasma physics), or they may be a useful starting point for deriving subgrid turbulence models for computer simulations. | |
| dc.description | 23 pages, LaTeX, submitted to Physics of Fluids. Maple worksheets available at http://w3.pppl.gov/~hammett/papers/2002/ | |
| dc.identifier | https://arxiv.org/abs/physics/0203031 | |
| dc.identifier | http://arxiv.org/abs/physics/0203031 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/84606 | |
| dc.subject | Fluid Dynamics | |
| dc.subject | Plasma Physics | |
| dc.title | Non-white noise and a multiple-rate Markovian closure theory for turbulence | |
| dc.type | text |