Hello,
I am simulating a shear cell using a servo wall as the top surface and a moving mesh as the bottom surface. The rotation period I set is some seconds.
Now, since I am scaling to lower dimensions (I have changed units to cgs as well, in order to avoid numerical limits), I have to reduce a lot the period in order to have a comparable tangential velocity, e.g. 100 times lower.
Well, when I am computing the torque exerted on the top surface (fix ... ave/time ... f_top[4] f_top[5] f_top[6] ...), the torques around the other axes increase to large values, even higher than the torque around the rotation axis.
What is the problem? Before (i.e. with large periods) their values were negligible. Is this related to the PID controller of the servo wall?
Thanks a lot for your help,
rob1