HYDRUS 2D PFAS MODULE: AWI area output is uniformally 0

[OHBratton]

Hello,

I have been working with the PFAS Module in HYDRUS 2D, and I have encountered an issue with the AWI values. It appears that the AWI is being output as 0 for the entire simulation even though the soil is not fully saturated. I have checked my PFAS module input parameters and the water content values and I can not see why this is occurring. Is this a known issue and/or does anyone have any ideas as to what might be causing this? I have attached two images below for reference, one with the water content and the other with the AWI, both at the same time step.

Water Content Output.PNG (99.01 KiB) Viewed 663 times

AWI Output.PNG (100.42 KiB) Viewed 663 times

Thanks,
OHBratton

[Jirka]

Currently, I’m not aware of any problem with calculating air-water interfacial area. I have switched PFAS on in the Furrow example (in 2D-Test) and the results are reasonable. J.

F1.png (121.71 KiB) Viewed 655 times

F2.png (152.39 KiB) Viewed 655 times

[OHBratton]

Thank you, Jirka, for the reply! Since the PFAS module and AWI Area are working in the Furrow example, it is almost certain the issue I am experiencing comes from some error in the way in which I set up my simulation. I will continue working with problem on my end and will post a follow up reply when I have a resolution so that others can avoid the same pitfall.

[Jirka]

Or post (or send me) your project so that i can have a look at it. From the figures, i can not conclude anything. J.

[OHBratton]

Apologies for the late follow up on my end, and thank you for offering to take a look at it! Unfortunately, the file is too large to upload to the pc-progress forum. Instead, I have emailed the file to your UCR email address.

Best,
OHBratton

[Jirka]

Owen,

You have specified the value of Scal_AWI, i.e., “a scaling constant k_m, to linearly scale the interfacial area A_aw” (text from help), equal to zero. The same Scal_AWI values must be used for all solutes (since the interfacial area, similarly as water content, is the same for all solutes). Actually, the Scal_AWI values given for the first solutes are used for all solutes. If you want to use different interfacial areas for different solutes, you need to run multiple simulations. You can not do that in one run.

J.

[OHBratton]

Thank you Jirka! I have changed Scal_AWI to 1 for solute 1 and the program is now working as desired!

-OHBratton