Pore compressibility issue in EOS9
Hello.
I have a quick question about EOS9.
Normally, the pore compressibility is used for considering specific storage due to pore volume change in TOUGH (at the MULTI subroutine).
However, I can't find the usage of the pore compressibility in EOS9 (at the MULTI_EOS9 subroutine).
I only find the value used for calculating hydraulic diffusivity for printing out on external data (in a print out subroutine, OUT of EOS9.f).
Priorly, I guess TOUGH just ignores specific storage (Ss), however, is considering only specific yield (Sy) for the unconfined aquifer, because Sy is much larger than Ss.
However, I'm sure I misunderstood ...this issue doesn't make sense in the sophisticated model.
Anyone gives me some clues?...
I will appreciate your kind answers.
Thanks
3 replies
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Sungho,Like in all EOS modules, pore compressibility is (or should be) accounted for in EOS9. I vaguely recall this having been an issue in the past, but has been resolved a while ago. I don't know which version of TOUGH2 you have, but you should have find the following code section in eos9.f (starting near line 1102):
1011 D(K,M)=0.
C
C-----COMPUTE CHANGE IN POROSITY.
IF (M.EQ.2) THEN
DPRES=DELX(NLOCP+1)
ELSE
DPRES=0.0D0
ENDIF
PRES=X(NLOCP+1)+DX(NLOCP+1)+DPRES
DPHI=PHIN*COM(MATX(N))*(PRES-P(N))
PHINN=PHIN+DPHIHope that resolves the issue.
Stefan
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Stefan Finsterle
Wow, it is an honor and thankful for the comment from the ITOUGH2's developer.
Basically, I use TOUGH2V2.1, TOUGHREACTV3.0, and ITOUGH6.9.
I've crosschecked EOS9 in them.
I know what you were saying, but I haven't found those lines in both EOS9.f and the MULTI_EOS9 subroutine, unlike the other EOSes (not using Richard eq.).
By the way, I tried to exercise an example (the fracture-matrix saturated-unsaturated flow problem) provided in TR-OMP.
It is a kind of sensitive test.
Case 1 is not considering pore compressibility (zero value), but Case 2 is considering pore compressibility (1.0E-5).
The results show same pore pressure and saturation filed, but different hydraulic diffusivity field.
It means that TOUGH doesn't account for pore compressibility in primary value calculation.
Thanks
Sungho
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Hi Sungho,
I'm confident that iTOUGH2 does include pore compressibility, also in eos9.f.
If you have the source code of TOUGH2 and TOUGHREACT, it should be easy for you to include the few lines that I showed in my previous reply. Otherwise, send me an e-mail and I will send you the corrected eos9.f for TOUGH2; contact Eric Sonnenthal regarding TOUGHREACT.
Cheers,
Stefan