benchmark01_rayleigh_benard
This benchmark considers the fluid instability that develops when a layer of fluid is heated from below and cooled from the top (see, e.g., Chandrasekhar 1961).
Input files for the benchmark are located in the {CORAL_ROOT}/etc/benchmarks/01_Rayleigh_Benard_stressFree.
The equations (and their linear stability) are detailed in this jupyter notebook.
Create a folder following the standard procedure, then copy the coral.* files there. Run the executable with a handful of cores. It stops after 10 minutes. One can then display the timeseries of kinetic energy:
python plot_volAvg_timeseries.py uu vv ww
An exponential growth is visible in both components of the kinetic energy, for t<0.4. Analytically, the growrate coefficient can be determined as a function of the horizontal wavenumber. The optimum is represented by the orange dot:
One may check the good agreement between the growthrate of the numerical solution (solid or dashed blue lines below) and the analytic, optimal growthrate (black horizontal dash-dotted line):
python linearGrowthrate_numerical_vs_analytical.py
