boundary condition for freely rotating cylinder on its own axis
 

I involve the study of the freely rotating cylinder under the force exerted by fluid flow. from my simulation which I done (screenshot attached), the cylinder is not fixed at its axis and moves in the direction of flow. However, I want the cylinder to rotate itself at its own axis and not move in the direction of flow.
To achieve this, I need to determine the boundary conditions for the freely rotating cylinder. Specifically, I am looking for information on how to set the boundary conditions to ensure that the cylinder rotates at its own axis and does not move in the direction of flow.
If anyone has any knowledge or expertise in this area, I would greatly appreciate your input. Any information, suggestions, or resources that you can provide would be extremely helpful.
Thank you in advance for your time and assistance.

https://drive.google.com/file/d/1l_M...oJCDmuWqr/view