For our Methane Hydrate code development project, now I am comparing OpenGeosys results with Code_Aster & Experimental Data . Our main purpose is to develop mechanical model for methane hydrate and to implement them in both OpenGeosys and Code_Aster. On the other hand, coupling performance of Code_Aster with TOUGH (HydrateResim) (internal and external coupling both) will be compared with the OpenGeosys considering the analogous modification in the both code (Code_Aster and OpenGeosys). The modification of THCM will depend on the Methane Hydrate project’s field data. The details of the project can be found here:
At present, OpenGeosys three elements are similar to Code_Aster (Quadrilateral, Hexahedron, and Triangular). In future if we need, any element from Code_Aster, I will implement them in OpenGeosys. I will also introduce similar modification for non-linear solver. After close observation I found, in both codes (OpenGeosys and Code_Aster), Liakopoulos test is common. To dig its bottom, I read following references
Liakopoulos, A.C. (1965) “Transient flow through unsaturated porous media”, PhD Thesis, Civil Engineering, University of California.
Narasimhan, T.N. and Witherspoon, P.A. (1978) “Numerical Model for saturated -unsaturated flow in deformable porous mdedia 3. Applications”, Water Resources Research, Vol 14, No 6, Page 1017-1034.
Gawin, D., Baggio, P., and Schrefler, B.A. (1995) " Coupled heat, water and gas flow in deformable porous media", International Journal for Numerical Methods in Fluids, Vol. 20, 969-987.
Gawin, D. and Schrefler, B.A. (1996) “Thermo-hydro-mechanical analysis of partially saturated porous materials”, Engineering Computations, Vol. 13 (7), 113-143.
Gawin, D., Simoni, L. and Schrefler, B.A. (1997) “Numerical model for hydro-mechanical behaviour in deformable porous media: A benchmaark problem”, Computer Methods and Advance Geomechanics, Balkema, Rotterdam, Page: 1143-1148.
Lewis, R.W. and Schrefler, B.A. (1998) “The Finite Element Method in the Static and Dynamic Deformationand Consolidation of Porous Media” Second Edition, John Wiler Sons, Page 167-174.
Schrefler, B.A. and Scotta, R. (2001) “A fully coupled dynamic model for two-phase fluid flow in deformable porous mdedia” Computer methods in applied mechanics and engineering, 3223, 3223-3246.
Granet, S. (2013) “WTNP124-Liakopoulos test case: Drainage of a column of water by the gravity force”, Code_Aster, V7.32.124, Revision: b2e73d847b87.
Now I have couple of questions:
a) Considering Triangular and Quadrilaeral element in xy and xz plane. It is found that only xz plane results are satisfactory. After generation of geometry, each and every time do I need to transfer xy plane data to xz plane? For your convenience, I attached data set for Quadrilateral element for both xy and xz plane.
b) In Code_Aster, the Liakopoulos case was simulated considering Hydrostatic Equilibrium condition considering gravity, while in OpenGeosys mechanical equilibrium condition is considered (to me more realistic !). I am wondering what is the procedure to obtain Hydrostatic Equilibrium condition in OpenGeosys? For your kind consideration, I attached Code_Aster Liakopoulos case in French and English (poor translation, sorry for inconvenience). I found that two files (*.ic and *. bc) need to modify to make it analogous to Code_Aster. Changing *.bc is straightforward and PRESSURE1 $DIS_TYPE (CONSTANT 101325). To achieve, Hydrostatic condition in *.ic file for PRESSURE1, $ DIS_TYPE changed to GRADIENT. But the results are far beyond the expectation. Is there any other way?
In O.Kolditz et al. “Thermo-Hydro-Mechanical-Chemical Processes in Fractured Porous Media, Lecture notes in Computational Science and Engineering 86, Chapter 13 (Consolidation Process HnM Process)”, page 283 (Figure 13.13)& Page 284 (Figure 13.14)are closely related to my case. Though HM condition, but the mechanism of Hydrostatic condition in Figure 13.14 is very close.
c)In Code_Aster Mualem-Van-Genuchten model used, but in OpenGeosys for Liakopoulos case Brook-Corey function is used. Unfortunately, Van-Genuchten model is not working (may be due to my lack of knowledge). To change the model, I modified *.mmp file as follows to achieve Van-Genuchten
What is the appropriate way to obtain Van-Genuchten model? I am interested to compare both result.
d) Finally, one very basic question: what is the difference between “TWO_PHASE_FLOW” & “MULTI_PHASE_FLOW” ?
Thanks in advance.
xz_xy plane.zip (1.2 MB)
v7.32.124_Eng.pdf (240 KB)
v7.32.124_French.pdf (263 KB)