Sebastian Remmler
17 records found
1
Authored
We present the results of fully resolved direct numerical simulations of monochromatic gravity waves breaking in the middle atmosphere. The simulations are initialized with optimal perurbations of the gives waves. Given a wavelength of 3 km, the required grid sizes range up to ...
Geophysical flows including stable stratification and system rotation are a special challenge for turbulence subgrid-sclae models for large-eddy simulation (LES) and hence require validation with suitable test cases. We validate different subgrid-scale models for this kind of ...
Benchmarking in a rotating annulus
A comparative experimental and numerical study of baroclinic wave dynamics
The differentially heated rotating annulus is a widely studied tabletop-size laboratory model of the general mid-latitude atmospheric circulation. The two most relevant factors of cyclogenesis, namely rotation and meridional temperature gradient are quite well captured in this ...
The analysis of the spectral eddy viscosity is a handy tool to analyze the performance of LES methods. It reflects the cumulated effect of numerical discretization and turbulence subgrid-scale model on the spectral energy transfer. We compute this quantity by filtering and tru ...
In order to evaluate turbulence subgrid-scale models for stably stratified flows, we performed direct numerical simulations (DNS) of homogeneous stratified turbulence with large-scale horizontal forcing. In these simulations we found that energy dissipation is concentrated wit ...
In order to evaluate turbulence subgrid-scale models for stably stratified flows, we performed direct numerical simulations (DNS) of homogeneous stratified turbulence with large-scale horizontal forcing. In these simulations we found that energy dissipation is concentrated wit ...
Spectral structure of stratified turbulence
Direct numerical simulations and predictions by large eddy simulation
Density stratification has a strong impact on turbulence in geophysical flows. Stratification changes the spatial turbulence spectrum and the energy transport and conversion within the spectrum. We analyze these effects based on a series of direct numerical simulations (DNS) o ...
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 vorte ...
Simulation of geophysical turbulent flows requires a robust and accurate subgrid-scale turbulence modeling. We propose an implicit subgrid-scale model for stratified fluids, based on the Adaptive Local Deconvolution Method. To validate this turbulence model, we performed direc ...