![airfoil group airfoil group](https://www.mh-aerotools.de/airfoils/images/velo6.gif)
You will typically create a finer mesh if you have a desktop or workstation available than if you just have a laptop. Adjust the mesh resolution to the available computational resources. Change refinement levels, regions, surfaces and layers to create a good mesh. Modify the rest of snappyHexMeshDict to suit your needs. The STL file can always be inspected in ParaView. Try to adjust the parameters and follow the changes.
![airfoil group airfoil group](https://tidbits.com/uploads/2016/02/airfoil-5-group.png)
All parameters are for simplicity located in the top of the script itself. The NACA2STL.m script will create a solid for any NACA 4-digit airfoil. - Highly experimental and wip: number of feature edge snapping Make sure that the features-section of system/snappyHexMeshDict looks like: system/snappyHexMeshDictĪnd that under snapControls there is a parameter system/snappyHexMeshDict Then snappyHexMesh will need to be "informed" about the edges and that it should snap to them. This will automatically detect any edges and produce a file constant/triSurface/airfoil.eMesh containing these. SurfaceFeatureExtract -includedAngle 150 -writeObj constant/triSurface/airfoil.stl airfoil That is done with the surfaceFeatureExtract-tool: Terminal window The first step is to extract the edges from the STL-file. To do this we will use the new edge handling feature. As the airfoil has a sharp edge of significant importance, we must make sure that this is resolved perfectly. The next step is to prepare for the meshing with snappyHexMesh. Put the file in the airfoil_snappyHexMesh/constant/triSurface directory. You might need to edit the first line in the script ( #!/usr/bin/octave -qf) if your Octave-binary is located in another location than /usr/bin. These commands will create a STL-file of a NACA0015 airfoil with a chord length of 1 meter. Download the script into a directory of your choice and make it executable.: Terminal window To save you for a lot of typing, an Octave-script NACA2STL.m has been made. It is not difficult to create a triangulated surface of this geometry: As the geometry of NACA airfoils is described by polynomial expressions, the coordinates of the airfoil surface can easily be calculated. Rm airfoil_pimpleFoam/constant/dynamicMeshDictīefore starting with the geometry definitions and mesh generation you might want to read about NACA airfoils at Wikipedia. Rm airfoil_simpleFoam/system/createPatchDict Mv wingMotion2D_pimpleDyMFoam airfoil_pimpleFoam Mv wingMotion2D_simpleFoam airfoil_simpleFoam
![airfoil group airfoil group](https://www.wdfxw.net/fileroot1/2018-12/25/1c54d9ca-6bfe-4b1a-a7f0-c546dba1f3a6/1c54d9ca-6bfe-4b1a-a7f0-c546dba1f3a61.gif)
Mv wingMotion2D_snappyHexMesh airfoil_snappyHexMesh The airfoil_simpleFoam/system/createPatchDict and the airfoil_pimpleFoam/constant/dynamicMeshDict can be deleted, because these functions will not be used here.Ĭp $FOAM_TUTORIALS/incompressible/pimpleDyMFoam/wingMotion. However, this stationary calculation is not necessarily correct, so one should always use good engineering judgements to assess the stationary solution before proceeding.Ĭopy the tutorial files over in a folder of your choice, rename the all folders so that their names get the correct meaning. This field is then used as the initial condition for a more computationally demanding transient solver. The advantage of this procedure is that one easily and effectively gets rid of the effects from non-physical initial conditions and quickly can calculate an averaged stationary flow field. This is because this tutorial uses two steps in the solution, first it calculates the stationary solution before it starts the transient solver. This time we will use the wingMotion tutorial as our basic case.