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TopicComments
SuperQuadrics: BoundingSphereRadius

Prolate ellipsoids don't work; Mercury does not detect overlaps;

this is because teh BoundingSphereRadius is miscomputed;

Dariel is looking at correcting that function, using the Alexander Podzhuk paper.

He needs to add special cases in if-statements.

Problems
  • outputting axis in setBoundingRadius results in wrong values
SuperQuadrics: Contact detection
  • Blockiness of 0.1 causes contact point detection to fail
  • The paper by Alexander P. on which the Mercury algorithm is based says convergence is guaranteed for blockiness >0.25
  • Dariel will take a look whether this can be fixed; but not priority
MercuryCG

Dariel reported a problem running MercuryCG on SuperQuadric particles (loadRestart does nto seem to work)

Thomas will take a look once he has Dariels restart files

Angle distributionDariel corrected the distribution of angles (relative to the velocity vector) by sin(theta)/2, but the data for spheres (AR=1) is not perfectly uniform (it should be); also, the data has a large standard deviation
  • I told him to use the data files instead of the restart files because they contain more timesteps; and look for errors
Surface velocity profilesDariel sees a  difference with aspect ratio in surface velocity profiles of mixed flows: The peak velocity is reached earlier for high aspect ratios. Unknown origin
Working Document

To write a paper, we need to understand what are teh two segregation drivers that cause  a flip in segregation direction at AR~3

Dariel should start a working document, where we keep results as they come in

For elongated particles, we always see an s-shaped curve, even at Fr=0.01; could it be a "rotation inertia" effect: flows are more frictional when particles still have to orient itself, are less frictional when elongated.

  •  Check whether angle of orientation w.r.t. streamlines of elongated particle vs r/R_0 shows a re-orientation of particles
  •  Find transition points rolling-cataracting as function of Froude and AR



Actions

  •  Dariel Hern├índez Delfin: correct the definition of BoundingSphereRadius in Mercury
  •  Dariel Hern├índez Delfin: make a shared Google Drive; put your existing results in (angle distribution, surface velocity profiles, cg data, snapshots); also include the restart files of simulations with different aspect ratio.