Abstract: High-resolution LES and U-RANS simulations of the cylinder wake flow in density driven gravity currents



Authors: Jan-Erik Melskotte

A Large Eddy Simulation of the three-dimensional circular cylinder flow in
a stratified two-phase-flow in  the scale of the experiment has been
performed parallel to laboratory experiments. The numerical simulation
allowed to overcome resolution limitations in the experiments, concerning
the spartial resolution and the available laboratory time budget. After
defining the boundary conditions the flow- and turbulence structures of
the wake were numerically simulated and compared with the data obtained
from the laboratory experiment. To extend the results from the laboratory
experiments and the hi-res LES simulation to the dimensions of the
original cylindric structure in the Baltic Sea, further simulations were
necessary. For this purpose an unsteady RANS (U-RANS) simulation in the
original scale of the Baltic Sea with boundary conditions adopted from IOW
measurements was performed. This approach successfully allowed the
analysis of the dominating structures of turbulence!
and the turbulence parameters in the wake, in the laboratory experiment
as well as in the natural scale.