Abstract: An infinite cylinder containing a fluid in solid body rotation (SBR) is impulsively stopped. The decay and self-organisation of the initial SBR due to the forming boundary layer and multiple transitions is addressed by means of direct numerical simulations for a wide range of Reynolds numbers. The flow undergoes five distinct flow stages during its decay, which are characterised by means of statistical evaluation. This database features statistics of four different spin-down simulations at different $Re$.
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Statistics on spin down for different Re
this database features:
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statistics of four different spin-down simulations at different Re=\Omega R^2/\nu;
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global volume-averaged data for turbulent kinetic engery (k), mean kinetic energy (K) and their budget equations;
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temporal evolution of 1D quantities such as wall-shear stress, boundary-layer thickness;
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temporal evolution of spatially (over z and \phi) averaged bulk data such as mean velocity, Reynolds-stresses etc.;
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terms of the k and K budget equations as function of t and r.
Acknowledgment:
The financial support by the German Research Foundation (DFG) under Priority Programme SPP-1881 is greatly acknowledged.
References:
F. Kaiser, B. Frohnapfel, R. Ostilla-Monico, J. Kriegseis, D. E. Rival and D. Gatti (2019)
"Flow stages during vortex decay in an impulsively stopped rotating cylinder",
Journal of Fluid Mechanics, (to be submitted)
Content:
folders for different Re: Re3000, Re6000, Re12000, Re28000
each folder contains:
tot.dat --> 1D data such as wall-velocity, boundary-layer thickness,
volume average K, volume average k etc.
t.dat --> time steps (spacing dt increases during late stages of decay)
r.dat --> radial positions of the grid
bulk --> folder: contains dat files for non-zero bulk quantities as functions of r and t.
mean velocity, mean vorticity, velocity in wall units, Reynolds stresses
mke --> folder: contains terms of the K budget equation as functions of r and t:
K, production, dissipation, turbulent transport, viscous transport
tke --> folder: contains terms of the TKE budget equation as functions of r and t:
k, production, dissipation, turbulent transport, viscous transport, pressure diffusion
Refer to the readme files in each subdirectory for further information on each database.
Changelog:
May-08-2019: database uploaded
frieder.kaiser@kit.edu
davide.gatti@kit.edu
bettina.frohnapfel@kit.edu
