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|ID||Project||Category||View Status||Date Submitted||Last Update|
|0002647||OpenFOAM||[All Projects] Bug||public||2017-08-03 10:43||2018-07-10 11:25|
|Status||closed||Resolution||no change required|
|Fixed in Version|
|Summary||0002647: frictional stress in kinetic theory modeling not taken into account|
|Description||Based on my understanding of the thesis of Berend van Wachem the frictional stress has to be taken into account for computing granular temperature equation. In twoPhaseEulerFoam only the granular part is taken into account.|
To be more specific the file in question is:
In line 388: the solid shear viscosity is computed based the table in van Wachems thesis (p.47 table 3.2). After that the viscosity is used to compute the solid stress tensor. However, in the thesis is stated (p.52 equation 3.27 and 3.28) that if the solid volume fraction is higher than a threshold value the frictional values have to be added. To my understanding this doesn't happen in the current implementation of the granular temperature equation.
The same issue occurs for the solid phase pressure later on in the same function. The pressure is computed due to p.45 eq. 3.22. However, the frictional pressure (p. 52 eq. 3.28) is not taken into account.
The frictional terms seem to be ignored intentionally which makes doubt whether I missed something or this part of the implementation is based on more recent publication. Nevertheless, I attached a kineticTheoryModel.C file which includes an in my opinion correct implementation. I ran the fluidized bed test case (RAS and kinetic Theory activated, equilibrium deactivated) with it and encountered no problems.
(van Wachem thesis : https://repository.tudelft.nl/islandora/object/uuid:919e2efa-5db2-40e6-9082-83b1416709a6/?collection=research )
kineticTheoryModel.C (15,024 bytes)
This issue was discussed a couple of years ago, see https://bugs.openfoam.org/view.php?id=1831.
thanks for your help. In this case the issue is resolved. Although I understand literature different. However, this has been discussed already.
|2017-08-03 10:43||Arne||New Issue|
|2017-08-03 10:43||Arne||File Added: kineticTheoryModel.C|
|2017-08-03 10:43||Arne||Tag Attached: multiphase|
|2017-08-03 10:43||Arne||Tag Attached: kineticTheory|
|2017-08-03 11:34||tniemi||Note Added: 0008502|
|2017-08-03 12:48||Arne||Note Added: 0008503|
|2017-08-04 11:14||henry||Assigned To||=> henry|
|2017-08-04 11:14||henry||Status||new => closed|
|2017-08-04 11:14||henry||Resolution||open => no change required|
|2017-08-04 11:14||henry||Note Added: 0008509|
|2017-08-04 11:14||henry||Relationship added||related to 0001831|
|2018-07-10 11:25||administrator||Tag Detached: kineticTheory|