courant number explosion on good mesh not shown in visual output

geth03 · October 15, 2021, 03:11

hi all,

i am running a simulation with reactingMultiphaseEulerFoam on OF version 7.

my Co keeps increasing from a certain time on, i could also say that my timestep is decreasing for a constant Co, i think the conclusion is the same. i did both, keeping Co constant and checking timestep and vice versa.

the strange part is that my mesh is really really good. also, when i try to visualize the high Co, the maximum value shown in paraview is really small, around 1, compared to what i see in the terminal output, which is 10, 20 or higher (depends on how far i let it go before stopping it, it increases with time).

i tried to modify the mesh, ran the case again and same thing happens.

does anybody have any idea why this happens?

regards.

geth03 · October 20, 2021, 09:54

the Co for multiphase cases is calculated for each phase and also for the total flux. the lib for Co takes only account the total flux, which is the reason that Co shown in the terminal does not match the ouput value from the lib.

October 15, 2021, 03:11	courant number explosion on good mesh not shown in visual output	#1
geth03 Senior Member Join Date: Dec 2019 Location: Cologne, Germany Posts: 355 Rep Power: 8	hi all, i am running a simulation with reactingMultiphaseEulerFoam on OF version 7. my Co keeps increasing from a certain time on, i could also say that my timestep is decreasing for a constant Co, i think the conclusion is the same. i did both, keeping Co constant and checking timestep and vice versa. the strange part is that my mesh is really really good. also, when i try to visualize the high Co, the maximum value shown in paraview is really small, around 1, compared to what i see in the terminal output, which is 10, 20 or higher (depends on how far i let it go before stopping it, it increases with time). i tried to modify the mesh, ran the case again and same thing happens. does anybody have any idea why this happens? regards.

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October 20, 2021, 09:54		#2
geth03 Senior Member Join Date: Dec 2019 Location: Cologne, Germany Posts: 355 Rep Power: 8	the Co for multiphase cases is calculated for each phase and also for the total flux. the lib for Co takes only account the total flux, which is the reason that Co shown in the terminal does not match the ouput value from the lib.