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Attendees (not all attendees listed as online)
- Timo Plath
Juan Esteban Alvarez- Mitchel Post
Sahar Pourandi- Mohammed Hassan
Hongyang ChengJulius Mbaziira- Thomas Weinhart
- Anthony Thornton
- Yousef Shaheenn
- Mohammad Reza Vesal
Igor
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Item | Notes | ||
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Multisphere | E-mail from Frank: Martijn and I have been looking at the rigid body rotations in MercuryDPM and especially the difference between how it is done for multispheres and other objects (including superquadratics). This is my current understanding: inertia_ is the initial moment of inertia matrix, rotation of a particle are encoded using a quaternion. For multispheres there is a master-slave relation between particles. The center-of-mass motion and rotation of a multisphere are stored at the master particle.
For multispheres the angularAccelerateMaster method is used, while for other particles angularAccelerate is used. Both function should do the same, but for different types of particles. angularAccelerateMaster seems fine to me (in principle), while angularAccelerate solves as Here I have used the subscript ‘lab’ to denote the laboratory frame of reference. It is related to the quantities in the frame of the ‘principal axis’ by a rotation, e.g. , where is the moment of inertial matrix actually used in the code. I think here a term is missing in the update performed by angularAccelerate! The (correct) equation of motion is
This is actually done in angularAccelerateMaster, but in the frame of the ‘principal axes’
I have a few remarks:
Here is in the principal axes frame of reference. For the quaternion we have, applying the quaternion algebra, and where vectors are treated as quaternions with zero scalar part. Note that the angular velocity in the principal axes frame of reference was used. Therefore the multiplication with the angular momentum vector is on the right ().
With kind regards, Frank
Update: still to do
MultiSphere will be reimplemented
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Coupling Branch | Three build systems. How to merge together.
Oomphlib Oomph-lib coupling works again; , using an external oomphlib oomph-lib directory and the vendor branch. | ||
Migration to git | We will move from svn to git, using gitlab.utwente.nl For everyone who is new to git or wants to know more about it: Git Course | ||
Tutorial 10 | Has no documentation, should be added Next MercuryMonth. | CMakeModules | Short discussion how they work |
Domain dec. | We keep to pixellated domain decomposition | ||
Force control | Hassan needs force-controlled walls, not unit cells; will think about implementing it; control should be the same. | Walton Braun |
Update: Reza is working on a independent controller that can be applied to anything (walls as well). |
Walls for superquadrics | Of interest to Mitchel. But, no-one is working in the implementation now. | ||
Combine parallel files | Martijn interested in that. Julius working on combined files; meanwhile there are codes to combine files in the Tools directory. | ||
Timo |
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CMake issue on Windows | Use cmake or ccmake from the command line instead of the gui. Workaround:
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Notes | New MercuryDPM website |