New question #248869 on Yade: https://answers.launchpad.net/yade/+question/248869
in a very speicific conditions one of my clump is getting a very high angVel and goes to a numerical instability. It seems, the problem is in this part of code [1] (leapfrogAsphericalRotate in NewtonIntegrator). I could minimize the problem and there are values of all variables during 2 iterations: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Iter:154675 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! A: 0.934319 -0.193747 0.299181 0.188102 0.980983 0.0478483 -0.302762 0.0115711 0.952996 M: 0.934319 -0.193747 0.299181 0.188102 0.980983 0.0478483 -0.302762 0.0115711 0.952996 state->angMom: 0 0 0 dt: 9.55301e-06 l_n: 0 0 0 l_b_n: 0 0 0 state->inertia: 6.16301e-08 1.15341e-07 1.25862e-07 angVel_b_n: 0 0 0 dotQ_n: 0 0 0 0 state->angMom: 0 0 0 l_b_half: 0 0 0 angVel_b_half: 0 0 0 dotQ_half: 0 0 0 0 state->ori: 0.9834 0.00922239 -0.153026 -0.0970739 state->angVel: 0 0 0 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Iter:154676 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! A: 0.934319 -0.193747 0.299181 0.188102 0.980983 0.0478483 -0.302762 0.0115711 0.952996 M: 0.934319 -0.193747 0.299181 0.188102 0.980983 0.0478483 -0.302762 0.0115711 0.952996 state->angMom: 7.9467e-07 4.00506e-06 0.00125804 dt: 9.55301e-06 l_n: 3.97335e-07 2.00253e-06 0.000629021 l_b_n: 0.000188175 3.21368e-05 0.000599357 state->inertia: 6.16301e-08 1.15341e-07 1.25862e-07 angVel_b_n: 3053.29 278.624 4762.03 dotQ_n: 238.374 1150.47 -33.1568 2576.39 state->angMom: 7.9467e-07 4.00506e-06 0.00125804 l_b_half: 0.000376349 6.42735e-05 0.00119871 angVel_b_half: 6106.58 557.247 9524.07 dotQ_half: 401.41 2300.23 -54.5905 5160.22 state->ori: 0.987234 0.0311965 -0.153548 -0.0477782 state->angVel: 2922.13 -527.866 10932.1 Can anybody understand, whether the problem in a very high state->angMom, which is obtained in a Iter=154676 or something else? Reducing the timestep does not solve the problem I remember, some years ago we had the same problem in clump-hopper-viscoelastic.py But it is not reproducible any more. Thanks ahead [1] https://github.com/yade/trunk/blob/master/pkg/dem/NewtonIntegrator.cpp#L253 -- You received this question notification because you are a member of yade-users, which is an answer contact for Yade. _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
