Mass diffusivity

epc1 · January 22, 2013, 21:10

Hello:

I´ve succesfully compiled and used a customized mass diffusion udf for a binary mixture. However when i extend the udf to 7 species i get a warning message that tells me the mass diffusivity is zero. The funny thing is that the user defined memories show the correct value for the variables that are used to calculate the diffusivities. Also, the diffisivity for the first 2 species is also being calculated and displayed correctly when i initialize the case.

Any thoughts on how i could solve this issue?

Thanks in advance.

kdep · April 1, 2016, 02:15

I'm sorry that I can't answer your question. Anyway you could share how you returned binary diffusion coefficients from your UDF? I can't seem to get my DEFINE_DIFFUSIVITY UDF to return anything but values for species i instead of species i in species j. Any help would be greatly appreciated.

Kurtis

January 22, 2013, 21:10	Mass diffusivity	#1
epc1 Member Ernesto Join Date: Dec 2011 Posts: 30 Rep Power: 15	Hello: I´ve succesfully compiled and used a customized mass diffusion udf for a binary mixture. However when i extend the udf to 7 species i get a warning message that tells me the mass diffusivity is zero. The funny thing is that the user defined memories show the correct value for the variables that are used to calculate the diffusivities. Also, the diffisivity for the first 2 species is also being calculated and displayed correctly when i initialize the case. Any thoughts on how i could solve this issue? Thanks in advance.

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April 1, 2016, 02:15		#2
kdep New Member Ontario Join Date: Mar 2016 Posts: 5 Rep Power: 10	I'm sorry that I can't answer your question. Anyway you could share how you returned binary diffusion coefficients from your UDF? I can't seem to get my DEFINE_DIFFUSIVITY UDF to return anything but values for species i instead of species i in species j. Any help would be greatly appreciated. Kurtis