dnsbox is a fortran code for the direct numerical simulation (DNS) of the sinusoidally forced Navier-Stokes equations (Kolmogorov flow) in a triply periodic domain.
To compile in a Linux environment, you need the development libraries of:
openmpi
fftw3
BLAS
LAPACK
and GFortran
(version 9 or higher).
On Ubuntu,
the packages "build-essential gfortran libfftw3-dev libopenmpi-dev libblas-dev liblapack-dev
"
should be sufficient.
To compile the simulator, do
make
Simulations are started from a pair of files:
state.000000
containing the state data and parameters.in
containing
the physical, output and debugging parameters.
Such a sample initial condition that leads to turbulence with a lifetime
longer than 10 000 is in test/
.
To run it, you can create a folder, say, rundir
,
mkdir rundir
copy the simulator binary (dns.x
), the initial condition (state.000000
) and the parameter input file
(parameters.in
) there,
cp dns.x rundir/
cp test/* rundir/
go to rundir
,
cd rundir
and run the simulator on N
cores, detaching from the terminal, and redirecting
stdout
(1
) and stderr
(2
) to the file log
,
nohup mpirun -np N dns.x > log 2>&1 &
Take note of the output process ID, say 123456
, you can use it to kill
the simulation,
kill 123456
unless it stops by itself due to laminarization, runtime limits (see parameters.in
)
or errors.
One can also start simulations from random initial conditions by setting IC
to -1
.
As the run goes on, it will write state files (state.123456
) and a file
containing observables and time-stepper data (stat.gp
).
To visualize stat.gp
, you can do
dnsstats ./ 0 -1
If you use dnsbox
in your research, please cite
- [YHB2021] G. Yalnız, B. Hof, N. B. Budanur, Coarse Graining the State Space of a Turbulent Flow Using Periodic Orbits. Physical Review Letters 126, 244502 (2021), arXiv:2007.02584.
-
N. B. Budanur, H. Kantz,
Scale-dependent Error Growth in Navier--Stokes Simulations. Physical Review E 106, 045102 (2022), arXiv:2209.01064. -
G. Yalnız, B. Hof, N. B. Budanur, Coarse Graining the State Space of a Turbulent Flow Using Periodic Orbits. Physical Review Letters 126, 244502 (2021), arXiv:2007.02584.