[api]

I am using dynamic mesh to simulate something that appears to look like a centrifugal pump (please see image1.jpg, attached).

I first ran simpleFoam using MRF until 4500 iterations. I then started a transient simulation using pimpleFoam with dynamic mesh. The simpleFoam results are ok. But the pimpleFoam solver reverses the direction of rotation of impeller midway during the simulation and changes the direction again. The specified direction of rotation in dynamicMeshDict is (0 1 0). I wanted to upload the animation file from paraview to show this, but I am unable to upload. Please let me know if you need any other information, and I will provide it.

I did notice that I have a 4% error in flowrate. I checked the flowrate between inlet and outlet at the last increment. I had specified a volumetric flowrate of 0.0005m3/s and the outlet is 0.000483m3/s. Also, I allowed the courant number to reach 8. Could this be an issue? Even if this is wrong, can the direction reverse automatically?

It would be good if I could know where I am going wrong.

I appreciate your help in advance. Thank you.

[api]

https://drive.google.com/file/d/1GJ2...x8yKkGZT_/view


sharing the animation file for reference