why i can not select the “add geometry operation” when i want to create external flow for my airfoil ?
Hi @hamdi_zaherali,
Welcome to the SimScale community!
If the “Add geometry operation” button is greyed out or unselectable when you are trying to create your external flow volume (wind tunnel enclosure), it is almost always due to one of these two reasons:
1. Incorrect File Format (STL vs. STEP) SimScale’s geometry operations require a solid mathematical CAD model. If you uploaded your airfoil as an STL or OBJ file, the platform reads it as a hollow, faceted mesh rather than a solid object. When this happens, boolean operations (like subtracting the airfoil from a block of air) are automatically disabled.
- The Fix: Make sure you are exporting your airfoil from your original CAD software (like SolidWorks, Fusion360, etc.) as a STEP (
.step/.stp) or Parasolid file, and upload that version instead.
2. You Need to Enter “CAD Edit Mode” SimScale’s workflow handles geometry modifications in a dedicated environment. If you are just clicking around the main simulation tree, the advanced geometry tools won’t be active.
- The Fix: Look at your imported geometry in the tree on the left side of the screen. Click the small blue pencil icon (CAD Edit Mode) next to your airfoil’s name. Once the CAD interface loads, go to the top menu and select Flow Volume Extract > External, set the dimensions for your virtual wind tunnel, and click Apply.
If you are already using a STEP file and still cannot select the operation in CAD Edit Mode, could you please share a link to your project? (Make sure the project permissions are set to Public).