under what circumstances would interFoam have alpha > 1?

yanxiang · February 21, 2013, 15:04

Dear Foamers,

As per the title, in OF211, what would make the alpha go above 1 when using interFoam? Shouldn't the MULES solver ensure the volume fraction be bounded at all times?

I constantly get unbounded alpha when trying to simulating a microscale reactor with good quality mesh. Sometimes it could go up to 6 or even higher if allowed to run longer. I partially solved the problem by changing the mesh/BC. However, it is good to know what causes this issue.

Thanks,
Yanxiang

duongquaphim · July 15, 2013, 16:29

Are you running cases with the same settings as in the damBreak tutorial? Could you put the case here such that I can give it a try? I never had any things like that.

Also for the term div(phi,alpha), using vanLeer01 instead of vanLeer might be helpful. This might also be helpful http://www.cfd-online.com/Forums/ope...erdymfoam.html

Regards,

Duong

February 21, 2013, 15:04	under what circumstances would interFoam have alpha > 1?	#1
yanxiang New Member Join Date: Mar 2012 Posts: 29 Rep Power: 14	Dear Foamers, As per the title, in OF211, what would make the alpha go above 1 when using interFoam? Shouldn't the MULES solver ensure the volume fraction be bounded at all times? I constantly get unbounded alpha when trying to simulating a microscale reactor with good quality mesh. Sometimes it could go up to 6 or even higher if allowed to run longer. I partially solved the problem by changing the mesh/BC. However, it is good to know what causes this issue. Thanks, Yanxiang lourencosm likes this.

July 15, 2013, 16:29		#2
duongquaphim Member Duong A. Hoang Join Date: Apr 2009 Location: Delft, Netherlands Posts: 93 Rep Power: 17	Are you running cases with the same settings as in the damBreak tutorial? Could you put the case here such that I can give it a try? I never had any things like that. Also for the term div(phi,alpha), using vanLeer01 instead of vanLeer might be helpful. This might also be helpful http://www.cfd-online.com/Forums/ope...erdymfoam.html Regards, Duong vbnhfylbh and lourencosm like this.

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