View Issue Details
|ID||Project||Category||View Status||Date Submitted||Last Update|
|0001841||OpenFOAM||Bug||public||2015-08-28 11:31||2022-05-18 11:10|
|Fixed in Version||dev|
|Summary||0001841: Abnormal Courant number and abnormal phase fractions in /multiphase/multiphaseInterDyMFoam/laminar/mixerVesselAMI2D|
|Description||MultiphaseInterDyMFoam has been executed for the case of mixerVesselAMI2D for the first time, the calculation has been terminated at Time=0.411847, though that endTime is set to 5 [s]. (Case1)|
I started to investigate the cause by changing the time step (deltaT) and when deltaT=5e-7 (for Case1, deltaT=1e-6) the calculation continued to Time=1.13274. (Case2) But I soon realised that it does not matter how small deltaT is: even though deltaT=1e-9, the calculation is terminated at around Time=0.4.
Then I compared the "alphas" of two cases (Case1 and Case2) using ParaView time by time and I found that air adjoining water seems to penetrate the impeller for Case 1 (See attached GIF file). For Case2, no such penetration is found.
The calculation log of the both cases, however, show abnormal Courant number and phase fractions before the run is terminated.
|Steps To Reproduce||When I tried 2 phases (air and water) instead of 4 phases, I could reproduce a similar phenomenon: abnormal Courant number and abnormal phase fractions before termination of calculation.|
So I guess, so far, that the combination of handling multiphase fluids with large difference of densities (1 kg/m^3 for air and 1000 kg/m^3 for water) and AMI interacts each other. In fact, I did not have such problem when I executed /multiphaseInterFoam/laminar/mixerVessel2D.
|Additional Information||The calculation of /multiphaseInterFoam/laminar/mixerVessel2D is normally ended: normal Courant number and normal phase fraction|
||This problem relates to the non-convervation problems with AMI for multiphase flow which have been reported and discussed here many times.|
Numerical issues with AMI-based patch couplings have been resolved by the new Non-Conformal Coupled (NCC) development. See the following commit for explanation, and instructions for how to use NCC and convert cases from AMI.
||File Added: mixerVesselAMI2D_Case1.gif|
|2015-08-28 11:39||henry||Note Added: 0005310|
|2015-08-29 15:01||wyldckat||Tag Attached: AMI|
|2022-05-18 11:10||will||Assigned To||=> will|
|2022-05-18 11:10||will||Status||new => resolved|
|2022-05-18 11:10||will||Resolution||open => fixed|
|2022-05-18 11:10||will||Fixed in Version||=> dev|
|2022-05-18 11:10||will||Note Added: 0012592|