Reservoir BC_Furrow Example

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Zak_T
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Location: Canada

Reservoir BC_Furrow Example

Post by Zak_T » Mon Jul 11, 2022 3:39 pm

Dear Jirka,

I have a few questions regarding the furrow example posted on HYDRUS website.

1.If the injection rate is variable, it should be entered in Var. F1 column in time variable BC table, correct?
2.Therefore, the program doesn't account for pumping or injection rate (-60 cm2/d) which was specified in the BC options>Reservoir BC menu,correct?
3.And if Var. F1 (-1440 cm/d) is assigned to the seepage face of the furrow, what does the value for Var. F2 (-1440 cm/d) represent?
4.The program account for Var. F2 and Var. F3 columns only if Var. F2 and 3 Boundary conditions are specified, correct?

Please let me know if there are any documents related to the rest of the reservoir BC examples that might help me simulate rain gardens using reservoir BC.

Thank you,
Zak

Jirka
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Location: USA
Location: Riverside, CA

Re: Reservoir BC_Furrow Example

Post by Jirka » Mon Jul 11, 2022 6:24 pm

I assume you refer to the FurrowBC example posted on:
https://www.pc-progress.com/en/Default. ... eservoirBC
Please that you can find answers to your questions in the help (topic – Reservoir BC). Let me copy here the text from the help:
Reservoir.png
Reservoir.png (26.2 KiB) Viewed 1525 times
1. Yes, it should.
2. Yes, it doesn’t.
3. As indicated in the help, the units are cm2/d.
4. Correct.

J.

Zak_T
Posts: 6
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Location: Canada

Re: Reservoir BC_Furrow Example

Post by Zak_T » Tue Jul 19, 2022 7:51 pm

Thank you so much Jirka.
I have 2 follow up questions that I couldn't figure out by myself please.

1. Does the injection rate (-1440 cm2/d) mean the injection rate (L/T) was multiplied by the length of boundary in the seepage face (2.2 cm from Boundary.OUT file)?

2. In results-other information> Cumulative fluxes> Cumulative Variable Boundary flux 1:
How does cum. var. fl of (-700 cm2) by end of 0.75 day calculated?

Your help is greatly appreciated.
Zak
Attachments
Var. F1.png
Var. F1.png (62.49 KiB) Viewed 1486 times
Cum Var. F1.png
Cum Var. F1.png (56.72 KiB) Viewed 1486 times

Jirka
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Re: Reservoir BC_Furrow Example

Post by Jirka » Tue Jul 19, 2022 11:06 pm

1. No. That is the inflow into the furrow (reservoir). That is only indirectly related to boundary fluxes. It is the flux Q_p in Figure 2.7 of the Technical Manual. Flux that you show is the flux (actual or cumulative) across the boundary, i.e., Q_in in Figure 2.7.
2. We have an inflow into the reservoir of 1440 cm2/d for one day, i.e., 1440 cm2. That means that the final infiltration (when all water from the furrow infiltrates) must be also 1440 cm2. Since we simulate only half of the furrow, the cumulative infiltration flux is half of that, i.e., about 720 cm2.
Note that in the project working folder, you can find the output file Well.out, which gives you volume and fluxes for the reservoir. See Table 11.10 of the Technical Manual.

J.

Jirka
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Location: Riverside, CA

Re: Reservoir BC_Furrow Example

Post by Jirka » Tue Jul 19, 2022 11:36 pm

Actually, it is slightly different. In the Furrow example, we limit when the inflow is turned off by giving the max allowed water level, which is the water depth in the furrow (in this case 10 cm). This is reached after about half day, and thus inflow is 717 cm2, infiltration is 712 cm2, and evaporation is 3 cm2. See the output file Well.out. J. 

Zak_T
Posts: 6
Joined: Thu Jul 07, 2022 5:03 am
Location: Canada

Re: Reservoir BC_Furrow Example

Post by Zak_T » Fri Jul 22, 2022 8:10 pm

Thank you again for your detailed response.

There might be an error while running Furrow BC using version 5.01.

1. I saved the original Furrow BC example as a new file and ran it, but I got completely different results in well.out file (i.e., infiltration and seepage columns) as per attached folder.

2. Can you please clarify why precipitation acting on the furrow is in L/T while injection rate is in L2/T?
I want to make sure I understand the physical meaning of the unit to use it properly.

Thank you again.
Zak
Attachments
Furrow Example_Version 5.01.zip
(534.95 KiB) Downloaded 144 times

Jirka
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Re: Reservoir BC_Furrow Example

Post by Jirka » Fri Jul 22, 2022 9:48 pm

You should disable the BC option “Apply Atmospheric BC to non-active seepage face”. We do not support that option anymore.

I have just run version 5.01.0640 and have not seen any problems. You should perhaps upgrade to this version.

Precipitation is always a surface flux and thus it is in units of L/T. Pumping/Injection is a flux into the reservoir (not associated with any boundary surface) and that’s why it has units of L2/T (for 2D) and L3/T for 3D.

J.

Zak_T
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Joined: Thu Jul 07, 2022 5:03 am
Location: Canada

Re: Reservoir BC_Furrow Example

Post by Zak_T » Tue Jul 26, 2022 4:59 pm

Hello Jirka,

Thank you for your time.

I disabled the BC option “Apply Atmospheric BC to non-active seepage face” and ran it using version 5.01.0640, but the issue was not resolved in well.out file as per attached folder.

Perhaps I should change something else to get the same results you got?

Thank you,
Zak
Attachments
Furrow Example_Version 5.01.0640.zip
(533.29 KiB) Downloaded 56 times

Jirka
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Re: Reservoir BC_Furrow Example

Post by Jirka » Wed Jul 27, 2022 8:34 am

I have started my vacation in Europe and will be here until the beginning of September. J.

Zak_T
Posts: 6
Joined: Thu Jul 07, 2022 5:03 am
Location: Canada

Re: Reservoir BC_Furrow Example

Post by Zak_T » Wed Sep 21, 2022 3:40 pm

Hello Jirka,

I hope you had enjoyed your vacation. Any updates on my previous question please?

Thanks,
Zak

Jirka
Posts: 5614
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Reservoir BC_Furrow Example

Post by Jirka » Thu Sep 22, 2022 9:11 pm

I have looked at the example and do not see any problems. This is the graph that I made using data from Well.out. This seems OK to me. J.
Attachments
F1.png
F1.png (24.7 KiB) Viewed 764 times

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