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IDProjectCategoryView StatusLast Update
0001841OpenFOAM[All Projects] Bugpublic2015-09-02 14:24
Reporteruser1226Assigned To 
PrioritynormalSeverityminorReproducibilityalways
Status newResolutionopen 
PlatformGNU/LinuxOSUbuntuOS Version14.04
Product Version 
Fixed in Version 
Summary0001841: Abnormal Courant number and abnormal phase fractions in /multiphase/multiphaseInterDyMFoam/laminar/mixerVesselAMI2D
DescriptionMultiphaseInterDyMFoam 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 ReproduceWhen 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 InformationThe calculation of /multiphaseInterFoam/laminar/mixerVessel2D is normally ended: normal Courant number and normal phase fraction
TagsAMI

Activities

user1226

2015-08-28 11:31

 

mixerVesselAMI2D_Case1.gif (204,488 bytes)
mixerVesselAMI2D_Case1.gif (204,488 bytes)

henry

2015-08-28 11:39

manager   ~0005310

This problem relates to the non-convervation problems with AMI for multiphase flow which have been reported and discussed here many times.

Issue History

Date Modified Username Field Change
2015-08-28 11:31 user1226 New Issue
2015-08-28 11:31 user1226 File Added: mixerVesselAMI2D_Case1.gif
2015-08-28 11:39 henry Note Added: 0005310
2015-08-29 15:01 wyldckat Tag Attached: AMI