Dataset to On the impact of spanwise inhomogeneous boundary conditions on secondary flows in turbulent channels

All simulation folders contain the input file(s) for the simulation as well as the time-averaged one-point statistics of the flow.

For all simulations, the following data is available:

• mean velocities <u>, <v>, <w>
• Reynolds stresses <u_i'*u_j*>, pressure correlations <u_i'*p'>
• Triple correlations <u_i'*u_j'*u_j'>
• Averaged terms of the balance of turbulent kinetic energy (TKE): Production P, Pseudo-dissipation psdiss, pressure transport ptr, turbulent transport ttrans, viscous diffusion viscdiff and mean convection mconv
• signed swirling strength swirl_signed
• Invariants eta, zeta for the Lumley triangle

as well as the averaging interval, and the y and z coordinates.

For some SSBC cases, time-averaged spectra have been included. Their generation is lined out in the thesis; the methods required for generating them from the raw source files are included in recreate_figures.py.

The dimension factors of the data have not been altered from the XCompact3D defaults. The dimension factor for velocity may be computed based on <u> (e.g. friction velocity, bulk velocity). The viscosity, which is required to make the TKE fields dimensionless (dimension factor u_tau^4/nu) is given as nu = 1/re_cl with re_cl = (re_tau/0.116)**(1.0/0.88).

A script to extract the data for the figures in the thesis is also included. This script queries the library described in the Appendix, pyxcompact. The following libraries are used (tested versions in parentheses):

• numpy (1.19.2)
• matplotlib (3.3.2)
• `scipy``(1.5.2) (for interpolation of fields)
• [optional] einsum2 (0.1) (increases performance of derivation calls)

The script has been tested with Python 3.7.6 and Python 3.8.5. It is called as follows: python recreate_figures.py.

On executing, some console messages, indicating that files are missing, will be printed. pyxcompact normally expects the raw output files of XCompact3D in the same folder as the input file; but then proceeds to load the time-averaged file into memory.