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Discussion items
Dariel gives presentation.
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- problem: s_c cannot be computed b/c of nan's. THis is likely b/c SuperQuadricParticle::getInteractionWith does return an interaction if the radii overlap, not if the particles are in contac (Solved).
Casually, Jurgen Besten emailed me reporting the same issue yesterday.
There was a bug in getContactWithSuperQuad; it used to create a contact even when it did not exist. - The spherical particles always have more kinetic energy in relation to the density than non-spherical particles no matter the direction where the segregation occurs. Thus, changes in contact stress gradient depending on the aspect ratio must be the cause of segregation direction flipping. Dariel Hernández Delfin will show that in next meeting.
- Dariel Hernández Delfin should create smoother colormap fields using more time steps in the coarse-graining calculation. The segregation index will be more accurate.
2020-9-23 Meeting notes Dariel
- Problem: Even after the last fix, there are still nan/inf values in the fstat files. These nan's in the fstat files cause nan's in the stat files.
Solution: Dariel Hernández Delfin: Check that the nan values in the fstat files are for contacts with zero force (i.e. they can be ignored). Remove them from the fstat file (e.g. sed -i 's/nan/0/g' *.fstat). Then your stat files should be without nan's - Problem: f^nu-phi^nu vs phi^nu plots are incorrect: f^nu-phi^nu should be 0 at phi^nu equal to 0 and 1, and the plots for spheres and ellipsoids should be point-symmetric (because f^sp+f^el=1, phi^sp+phi^el=1).This must be a bug
Solution: Dariel Hernández Delfin should find the bug. - Dariel showed me plots that show a quite clear correlation between segregation strength and contact overstress f_c^nu-phi^nu, not with kinetic-overstress.
To show this clearly: Dariel Hernández Delfin plot overstress f^nu-phi^nu as a function of aspect ratio (for both kinetic and contact). You could limit the data to phi^nu values between 0.4 and 0.6 to get reliable data for such a plot. - Problem: The overstress behaviour seems different near the drum wall
Solution: Dariel Hernández Delfin color the data taken from near the wall differently, so we can distinguish. - Problem: Raul cannot see the notes I think
Solution: Thomas Weinhart Get Raul to sign up to confluence.
2020-10-7 Meeting notes Dariel
- Plots are now symmetric. Data shows two competing mechanisms, f^c-f^k and f^k-phi.
- We should add Chute data
- Suggestion for Mercury by Raul: estimate contact point of superquadrics with spherocylinder
- Suggestion by Raul: You can define quite general shapes using spherocylinders with a variable radius.
2020-11-4 Meeting notes Dariel
- Note: Deepaks paper predicts segregation even in the non-sheared regions; there is a shear-rate dependency missing; so we should only consider the sheared flowing layer. (There is a draft paper by Deepak showing dependence on I)
- V_r shows no flip in segregation directions; but, see above, it should be averaged only over the flowing layer.
- Dariel Hernández Delfin redo the plot. Also replot numerator and denominator separately.
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