External flow generation error

Hi there.

I have a problem for generating the external flow of my model. The model is to be simulated for its rotational situation, the external flow is necessary with the cylinder and the rotor file. My CAD file with three blades are inserted in the project, I know it has the surface which is not perfectly trimmed, I left it because if I delete those faces, the geomery become incomplete in Onshape and CAD mode in Simscale. (It becomes “Surface”, rather than “Part”, which would ultimately make the simulation impossible) If the problem is not from the geometry, then please let me know the reasons for this.
Can you tell me how I can solve this issue so that I can make the simulation operated within my project due date?

  1. Error Situation
  2. Suscepted part for the error

Project name: “0105_3Blade_”
Marked with “Share with support”

Thanks always in advance!
Best, Kim

The same problem also happens with my propeller rotation simulation setting.

Project name : 0106_comp

Hello Kim!

This error is caused because all three blades are intersecting with the hub geometry. Once you use Interferences tool in the CAD mode, you will see all three intersecting parts. Usually Fix Interferences operation should work without any error, but I noticed a partial intersection between Part 7 (one of the blades) and the hub geometry that causes an error.

To resolve these issues step-by-step:

-Please use Move command in the CAD mode to extend the root face of the Blade Part 7 with a distance of reasonably small value so that the blade and hub geometry will be intersecting completely,

-Then use either Fix Interferences, or Boolen/Subtract operation for each blade part in the CAD mode. I would prefer the second one in this case since I want to be able to select Tool and Target bodies.

Upon completion of these operations, external flow region should be performed without issues.

Please let us know how it goes,

Dear Kaan
Thank you for the help! I fixed the interfaces of two blades but Part 7 still matters.

The fan itself is one body, it is hard for me to separate them to avoid the errors in the images. Can you share some insights to solve this interfaces problem? (Boolean, Fix interfaces doesn’t work.)

Happy Friday!
Best regards, Kim

Hello Kim,

Instead of Up to Entity option, I went with a Distance method in Move operation. I have used a very small value of distance (1e-4) so that it won’t cross over the hub geometry, then used the boolen/subtract operation. I just shared my own edit of the geometry with your platform account in case you want to take a look.

Hope this is helpful and thanks for the good wishes.

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Thank you Kaan! Your perfect answer helped me perfectly!
Teşekkür ederim :slight_smile:

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