GMO _problem from rotational angle
 

I have a GMO rocking around fixed(Y) axis. It is observed that when the rotational angle is all positive or all negative then the oscillating x force is in reasonable range. but when this rotational angle oscillates from -M to +M value the resulting x-force is nearly zero . why? Please suggest something to fix this issue. thanks
Here the GMO is moving under prescribed sinusoidal velocity.

Jiko,

I am not sure I grasp the geometry of the motion. Do you have an prepin please?

Thanks M,
Here is the prepin file attached. the phase of 270degree is to rock the GMO evenly on both sides of the initial position. observe the x-force for 0 phase and for 270phase.

thanks.
waiting for your reply.
J

Thanks for the file. The first thing I'd suggest is not using the GMRES implicit viscous solver. It does not produce reliable solution and needs further work. In fact, I don't think you need an implicit viscous solver at all. An explicit solver is always better if it does not limit the time step too much. In your case the fluid is water, so I am sure the time step stability is controlled by convection rather than viscous dissipation.

Let me know if it behaves differently with the explicit sovler.

i'll check it out this weekend

Yes, sorry, will check it out as soon as I can.

Mike

Jiko, I ran it as you sent me and get a pretty substantial force in the x-direction. So far it is just short of 5 seconds. See the plot

Thanks for your time Michael, I wonder why on my PC it turns out to be much different. I would be grateful if you could send me the prepin used for these results from your end.
thanks

Jiko, it is the same file you sent me. I ran it with version 10.0 of FLOW-3D. Version 9.4 should give the same results.

thanks Mickael, so its mean that version 10 solves my problem.

I hope so...