I have always had a hard time finding the coordinate for a circle center in Simcenter STAR-CCM+. I have usually been forced to go back and “find” the coordinate in a pre-processing program. But there is way in Simcenter STAR-CCM+ that allows you to do this.
Assume you want to apply an actual rotation to a cylinder. Whether or not you move the mesh or simply apply a velocity specification to the wall you will want to know around what axis the cylinder should rotate.
This can be done by graphically creating a cylindrical coordinate system. Start by showing the mesh on your geometry. Then go to tools -> Coordinate Systems -> Laboratory -> Local coordinate systems. Right click the last folder and select New -> Cylindrical.
Once you do the following window will be visible to you. In that window you select the button in the picture, the one marked that allows you to select tree point on a circle to define a coordinate system.
Once you have selected that option you will get a preview of the coordinate system. What you do then is simply select three points in the edge of the circle. Make sure you select a point where edges meet (if you do the selection will become green). And once you have selected three points on the circle the coordinate system is automatically created with all necessary information in the edit window.
The actual center point of the circle can be found in the coordinate system origin box. You can now create another coordinate system in the other end of the circle to get two points and let that define a rotational vector. Or you can use your newly created coordinate system and apply your rotational motion to that one.
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