[Mamadsaleh]

Dear CFD-community,

I have set up a multiphase simualtion for a rectangular channel.
It works perfect (see zipfile "01_chennel_Mo_nut_0.02 - Kopie"). After that I just have changed the "nut" file for adding the roughness (Ks and Cs ...) and the simulation works for some timesteps and then it stops (see zipfile "02_chennel_Mo_nutkRoughWallF_ks_0.01"). The message is to long so I paste just an small part of it :

Courant Number mean: 0.160202 max: 5.84469
Interface Courant Number mean: 0.00963411 max: 4.0877
deltaT = 0.0029037
Time = 0.662252

MULES: Solving for alpha.water
Phase-1 volume fraction = 0.429972 Min(alpha.water) = -0.0460261 Max(alpha.water) = 1
MULES: Solving for alpha.water
Phase-1 volume fraction = 0.430009 Min(alpha.water) = -0.0641376 Max(alpha.water) = 1
MULES: Solving for alpha.water
Phase-1 volume fraction = 0.430045 Min(alpha.water) = -0.0762846 Max(alpha.water) = 1
GAMG: Solving for p_rgh, Initial residual = 0.0109182, Final residual = 3.54955e-05, No Iterations 2
time step continuity errors : sum local = 7.04264e-05, global = -3.02566e-06, cumulative = -0.00251685
Generating stack trace...


Backtrace:
ZN10StackTraceC1Ev [0x626c1855+0x25]
module: C:\PROGRA~1\BLUECF~2\ThirdParty-8\platforms\mingw_w64GccDPInt32\lib\libstack_trace .dll
ZN4Foam5error10printStackERNS_7OstreamE [0x6c30ae5a+0x23a]
module: C:\PROGRA~1\BLUECF~2\OpenFOAM-8\platforms\mingw_w64GccDPInt32Opt\lib\libOpenFOAM .dll
ZN4Foam6sigFpe13sigFpeHandlerEi [0x6c30b693+0x33]
module: C:\PROGRA~1\BLUECF~2\OpenFOAM-8\platforms\mingw_w64GccDPInt32Opt\lib\libOpenFOAM .dll
(No symbol) [0x417202]
...


The Courant number is not so big. I changed the timesteps more than 30 times form bigger to smaller one and vice versa.

I have refined the mesh and changed the value of Ks. But at some place between .55 sec to 0.65 sec it stops.


Simulations can be downloaded hier:
https://drive.google.com/drive/folde...DE?usp=sharing

Any help will be appricated.

[Mamadsaleh]

I solved myself the problem. Taht was because of structured Mesh, which I used. I changed the mesh into unstructured and it works again perfectly.