Test cases

This case is designed to verify that a scheme can capture complex physical phenomena resulting from the interaction between a strong vortex and a shock wave. This is a two-dimensional unsteady inviscid flow including multiple shock discontinuities. When the strong vortex and the strong shock wave encounter, considerable distortion of shock structure occurs, followed by the generation of linear and non-linear waves propagating onto the downstream flow fields. Two distinctive physical phenomena can be observed in this problem. First, the strong vortex is split into two separate vortical structure due to the compression effects of the shock passage. The post-shock vortical structure depends strongly on the relative strength of the shock and the vortex. Second, cylindrical acoustic wave structure appears on the downstream side of the stationary shock. The sound waves centered on the moving vortex core are partly cut off by the shock wave. As a result, alternating expansion and compression regions are observed.

Andrei Cimpoeru has generously provided a python script that can be used to generate the intial conition for this test case.

Please follow the presentation guidlines when creating your presentation.

UPDATE: July 5 2017: Expression for initial condition rather than a rounded number.

Meshing information:

In the cases of CGNS format, grid files (.cgns) are provided directly. Participants can use them without any pre-processing.
In the cases of GMSH format, GMSH script files (.geo) are provided. Participants can generate each type of meshes by using the GMSH script files and the GMSH program.
In the cases of both "M" and "IT" type meshes, follow the instuctions provided in each GMSH script file to apply a certain meshing algorithm (i.e. Delaunay).
In GMSH script files, participants can modify the variable "nx" to change the grid size.
For example, if you want to generate "RQ100" mesh, insert "100" into "nx" in the "RQ.geo" file.

Physical boundary conditions are set as follows:

. GMSH-type grids:

            73
      ---------------
     |               |
  74 |               | 72
     |               |
      ---------------
            71

. CGNS-type grids:

                            "Wall"
                       ---------------
                      |               |
  "Inflow Supersonic" |               | "Outflow Subsonic"
                      |               |
                       ---------------
                            "Wall"

The common research model (CRM) was extensively studied with state-of-the-art CFD codes in the sixth drag prediction workshop (DPW-6). The objective of this test case is to obtain mesh-converged lift, drag and moment coefficient values on the CRM wing-body configuration at cruise conditions. This test case is primarily intended to assess hp-adaptation schemes, but fixed grid results are also welcome. A series of curved finite element methods are provided, and a large number of grids on the DPW-6 website available with various grid topologies. In addition, Steve Karman of Pointwise has provided a set of curved meshes here in CGNS and gmsh file formats. As the CGNS standard is vague on the reference coordinate location of face coordinates of quartic (P4) tetrahedral elements, the CGNS files provided by pointwise uses equidistributed nodes on the reference element.

Please follow the presentation guidelines when creating your presentation.

This test case concerns the spanwise periodic DNS or LES of the transitional and separated flow on the T106A and T106C subsonic turbine cascades. These are well-known test cases for assessing transition models for low Reynolds numbers. The first test case concerns the T106A at Re=60.000, while the T106C is computed at Re=80.000. As the inlet turbulence is very low, both flows feature laminar separation and transition in the reattachment zone or in the wake.

Although mesh configurations are fully free, cascade CAD files (igs, stp) as well as curved meshes (unstructured and extruded triangular/quadrilateral) can be provided on request.

The NASA rotor 67 is a well-known validation test case for turbomachinery CFD codes.  The aim of this challenge is to see whether fully unstructured high order simulations can be performed.

A first type of contribution concerns the generation of the curved (hybrid) unstructured meshes for a single passage.  The requirements are

• minimally quadratic interpolation of the geometry;
• local mesh refinement following size control maps in leakage flow regions;
• curved rotationally periodic boundaries;
• extrusion curved boundary layer meshes, with an aspect ratio up to 1000 for RANS.

For meshing purposes the CAD of a single passage with and without tip gap is available in parasolid and step format. The full rotor has 22 blades.

The second type of contribution concerns the actual RANS/LES/WMLES computation at two operating points, ie. near the design point and near stall. The computation will at least be taken up by the test case leader.  For computational contributions, block structured curved meshes will be provided on request.