Unexpected water content and temperature in WUFI 2D

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WEI LI
WUFI User
WUFI User
Posts: 35
Joined: Thu Oct 29, 2020 1:02 pm -1100

Unexpected water content and temperature in WUFI 2D

Post by WEI LI » Mon Apr 04, 2022 10:57 pm -1100

Hi WUFI team,

Please help, I am desperate. Below is the geometry representing a ventilated roof. I have metal decks on both sides of the roof. For the cavity (in light blue), a 250 ACH air change source was applied. The pink part is the PIR board and liquid distribution coefficients were applied to it.
Geometry.png
Geometry.png (27.72 KiB) Viewed 200 times
I ran a one-year simulation. The thing is, every variable in every place is unbelievably repeating in a short period of time. Please see the pics below.
The temperature of the outermost metal deck:
temperature of outermost.png
temperature of outermost.png (144.3 KiB) Viewed 200 times
Water content of the PIR board:
watercontentPIR.png
watercontentPIR.png (82.87 KiB) Viewed 200 times
At least I would expect that the temperature would vary with the season, but not.
I do not think the settings are the problem cause they are almost all by default, except for the explicit radiation is turned on.
Could anybody please help me? thank you!

WEI LI
WUFI User
WUFI User
Posts: 35
Joined: Thu Oct 29, 2020 1:02 pm -1100

Re: Unexpected water content and temperature in WUFI 2D

Post by WEI LI » Wed Apr 06, 2022 12:27 am -1100

I highly suspect it was a numerical issue.
Any clues? Thanks!!

Thomas
WUFI Administrator
WUFI Administrator
Posts: 365
Joined: Sun Jun 19, 2005 10:33 pm -1100

Re: Unexpected water content and temperature in WUFI 2D

Post by Thomas » Wed Apr 06, 2022 2:34 am -1100

Hi WEI LI,

this may be a bug causing a wrong time step size. Please see here for a solution: Wrong timestep in climate file.

Kind regards,
Thomas

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