Direct and large eddy simulation of stratified turbulence
| Autor: | Sebastian Remmler, Stefan Hickel |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Fluid Flow and Transfer Processes
Physics K-epsilon turbulence model Mechanical Engineering Stratified flows Direct numerical simulation Turbulence modeling Reynolds stress equation model Mechanics K-omega turbulence model Condensed Matter Physics Nonlinear Sciences::Chaotic Dynamics Physics::Fluid Dynamics Turbulence kinetic energy Statistical physics Large eddy simulation |
| Zdroj: | Delft University of Technology |
| ISSN: | 0142-727X |
| Popis: | Simulations of geophysical turbulent flows require a robust and accurate subgrid-scale turbulence modeling. To evaluate turbulence models for stably stratified flows, we performed direct numerical simulations (DNSs) of the transition of the three-dimensional Taylor–Green vortex and of homogeneous stratified turbulence with large-scale horizontal forcing. In these simulations we found that energy dissipation is concentrated within thin layers of horizontal tagliatelle-like vortex sheets between large pancake-like structures. We propose a new implicit subgrid-scale model for stratified fluids, based on the Adaptive Local Deconvolution Method (ALDM). Our analysis proves that the implicit turbulence model ALDM correctly predicts the turbulence energy budget and the energy spectra of stratified turbulence, even though dissipative structures are not resolved on the computational grid. |
| Databáze: | OpenAIRE |
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