Is it possible to decide and know which liquid transfer coefficient (suction & redistribution) is used in WUFI calculati

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yuan
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Is it possible to decide and know which liquid transfer coefficient (suction & redistribution) is used in WUFI calculati

Post by yuan » Thu Mar 14, 2019 8:11 pm -1100

Hello~
Thank you for your attemtion.

I wrote a Fortran programme use WUFI equation to solve an 1D question (with initial condition are temperature 10C and rh 0.6 and constant indoor and outdoor temperature 10 C and relative humidity 0.6, 0.8 ). I use different liquid transfer coefficient(suction & redistribution) to do calculation and compare those two results with WUFI results, it showed that the WUFI software results match better with the “suction” results. But there is no rain was set in the simulation. As I know, “suction” happened only when there is driving rain. I think it is not reasonale.
I was wondering can I decide which coefficient is used in WUFI simulation? I cannot unlock material data, is it possible in WUFI light or only can happened in full version WUFI Pro?

Here is the compare result of my programme and WUFI:
Image
thank you so much for your kind help.

Lu
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Christian Bludau
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Re: Is it possible to decide and know which liquid transfer coefficient (suction & redistribution) is used in WUFI calcu

Post by Christian Bludau » Thu Mar 14, 2019 8:21 pm -1100

Dear Lu,
WUFI uses two liquid transfer coefficients (suction & redistribution) and as you wrote it is switched using the rain in the boundary condition. To use a different one you would have to change the coefficients in the material data.
In WUFI light it is not possible to edit material data or enter new ones. Therefore you would need the full version.
Christian

Thomas
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Re: Is it possible to decide and know which liquid transfer coefficient (suction & redistribution) is used in WUFI calcu

Post by Thomas » Thu Mar 14, 2019 10:20 pm -1100

Hi Lu,

moisture transport in WUFI always is the sum of liquid transport and vapor diffusion. For a reference solution in which only liquid transport occurs, you must suppress vapor transport in the material by setting the mu value of the material to a very high value (9e9, say). Also set the sd-values of both surfaces to very high values (9e9, say) to avoid vapor exchange between the component and the surroundings.

Regards,
Thomas

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