Release Notes

The 0.6.0 release of Aither is available on Github. This release adds periodic boundary conditions and wall functions for turbulent flow. Wall variables can now be output to Plot3D meta files as well. Additional test cases have been added for Couette flow and wall functions. The wall functions are available for the k- Wilcox, SST, SST-DES, and WALE turbulence models. The wall functions are implemented in the way described by Nichols & Nelson [1]. If the first cell off the wall is in the log layer, the wall shear stress is prescribed by the wall of the law.

If the first cell off the wall results in a less than 10, the boundary condition automatically switches back to the low Reynolds number formulation.

Wall variable output can be requested by assigning a list of variables to the wallOutputVariables input. Wall functions can be turned on by setting the wallTreatment option for a viscousWall to wallLaw as shown below.

wallOutputVariables: <yplus, heatFlux, shearStress, frictionVelocity>
boundaryStates: <viscousWall(tag=1; wallTreatment=wallLaw)>

Features Added

  • Periodic boundary conditions
  • Wall functions for turbulent flow
  • Wall variables output
  • Test cases
    • Couette flow
    • Flat plate wall functions


[1] Nichols, R. H. & Nelson, C. C. “Wall Function Boundary Conditions Including Heat Transfer and Compressibility”. AIAA Journal, Vol 42, No 6, June 2004.