Propeller
Introduction
- This example uses BaramMesh to create the mesh of a propeller from the pimpleFoam tutorial on OpenFOAM.
- To compute as a sliding mesh, we have a cylinder surrounding the propeller and set its interior as a cellzone. The surfaces surrounding the cellzone must have two interfaces at the same location.
Geometry
Use given 3 stl files of propeller.stl, propelerStem.stl, far.stl as geometry.
far.stl is a cylinder for computational domain, but the flow in and out is not separated, so you need to separate the boundaries when reading it.
Click the [Import] button at the bottom and select propeller.stl and propellerStem.stl files.
Click the [Import] button at the bottom to select far.stl file and turn on [Split Surface] option.
With the default Feature Angle of 60, you can see that the surface is divided into three parts: entrance, exit, and farfield. Press the OK button.
split surface
In Geometry, select far_surface1 and right-click and select Edit/View. In the window that opens, change the name as outlet.
In Geometry, select far_surface2 and right-click and select Edit/View. In the window that opens, change the name as inlet.
Create cylinder for cell zone
To create cell zone for sliding mesh, click [Add] button. Select [Cylinder] and set values as follows
- Name : cellZone
- Type : CellZone
- Cylinder Geometry
- Axis Point1 : (-0.06 0 0)
- Axis Point2 : (0.08 0 0)
- Radius : 0.12
In Geometry, select cellZone_surface and right-click and select Edit/View. In the window that opens, change the type as [Interface]-[Non-Conformal].
Create cylinder for refinement
Click [Add] button and select [Cylinder] and set values as follows
- Name : refine
- Type : None
- Cylinder Geometry
- Axis Point1 : (-0.1 0 0)
- Axis Point2 : (0.6 0 0)
- Radius : 0.16
In Geometry, select refine_surface and right-click and select Edit/View. In the window that opens, change the type as [None].
The final geometry looks like this
Click the [Next] button to move on to the next step.
Region
Click the (+) icon at the top to create a region. Move the mouse to the intersection of the lines that appear in light green color in the graphics window and position it inside the computation domain. Click the [Add] button to complete the setup.
Click the [Next] button to move on to the next step.
Base Grid
Set the number of grids to 20, 120, and 12. Click the [Generate] button to generate the base grid.
Click the [Next] button to move on to the next step.
Castellation
Surface/Feature Refinement
Use level 4~6 for propeller, 4 for stem and cellZone, and 3 for refine.
Click the (+) icon under [Surface/Feature Refinement] and set the following settings for propeller
- Surface Refinement
- Minimum Level : 4
- Maximum Level : 6
- Feature Edge refinement Level : 4
- Surfaces : propeller
Click the (+) icon under [Surface/Feature Refinement] and set the following settings for propellerStem and cellZone
- Surface Refinement
- Minimum Level : 4
- Maximum Level : 4
- Feature Edge refinement Level : 4
- Surfaces : propellerStem, cellZone_surface
Click the (+) icon under [Surface/Feature Refinement] and set the following settings for refine
- Surface Refinement
- Minimum Level : 3
- Maximum Level : 3
- Feature Edge refinement Level : 3
- Surfaces : refine_surface
Volume Refinement
Set the level 4 for cellZone and 3 for refine.
Click the (+) icon under [Volume Refinement] and set the following settings for cellZone
Click the (+) icon under [Volume Refinement] and set the following settings for refine
Click the [Refine] button and the castellation step starts.
Click the [Next] button to move on to the next step.
Snap
Change the [Feature Snap Type] under [Feature Snapping] to [implicit] and click the [Snap] button to start snap.
Click the [Next] button to move on to the next step.
Boundary Layer
Add boundary layer at propeller and propellerStem.
Click the (+) icon under [Configuration] to add a [Setting], and set it as follows
- Number of Layers : 3
- Thickness Model Specification : First and Expansion
- Size Specification : Relative
- First Layer Thickness : 0.1
- Expansion Ratio : 1.2
- Min. Total Thickness : 0.2
- Boundary : propeller, propellerStem
Use default settings for [Advanced Configuration].
Click [Apply] button to start boundary layer step.
Click the [Next] button to move on to the next step.
Export
Click [Export as BaramFlow project] to export the mesh to the desired location.