## REYNOLDS DECOMPOSITION OF TURBULENCE CONTAINING SUPER-COHERENT STATES
## 要約A vexing problem occurs in certain flows when long, but finite,
time-average estimates of the mean flow fail to exhibit the symmetry properties imposed by boundary conditions and physics. The mean field becomes suspect, making it difficult, or even incorrect to apply Reynolds decomposition. The problem occurs when the flow exhibits "super-coherent" states, i.e. states of flow having coherence times much longer than the averaging times used in typical turbulence experiments. Turbulent Rayleigh-Benard convection (RBC) is one such flow, and it will be used here as an example to illustrate and explain this phenomenon. The study focuses on a turbulent RBC experiment (Fernandes, 2001) in a 6.3:1 (diameter: depth) aspect-ratio vertical cylinder that supplemented time averaging with true ensemble averaging to achieve almost zero mean flow. To obtain a three-dimensional time-varying picture of the mechanisms
at work, the experiment is simulated by direct numerical simulation of the Boussinesq equations (Sakievich |

TSFP DL Home | アーカイブ | 執行委員会 |