Examples
All benchmarks, examples and applications cases to be run by Kratos. Note that unit tests are in Kratos repository and NOT here
Fluid flow in pre-existing fractures network
Author: Ignasi de Pouplana
Kratos version: 9.3
Source files: Fluid Pumping 2D
How to run: from terminal using python or from the GUI using GiD.
Case Specification
This problem consists on a 30 x 15 m block of soil with a pre-defined fractures network of 4 cm width through which a constant flux of water is pumped at 1 m/s during 0.001 seconds.
The example is approached in a 2D configuration under plane-strain assumption and combines two different types of elements. The porous domain is represented by standard displacement-pore pressure elements and the pre-existing fractures network is defined by interface elements, which represent the jump in the displacement field and introduce directional preferences in the fluid flow [1].
The material properties of the porous domain are the following:
- Young’s modulus (E): 2.6E+7 N/m2
- Poisson’s ratio (ν): 0.2
- Solid density (ρs): 2000 Kg/m3
- Fluid density (ρf): 1000 Kg/m3
- Porosity (φ): 0.3
- Solid bulk modulus (Ks): 1.0E+10 N/m2
- Fluid bulk modulus (Kf): 2.0E+7 N/m2
- Intrinsic permeability (k): 4.5E-11 m2
- Dynamic viscosity (μ): 0.001 s·N/m2
While the joints are represented by the following properties:
- Young’s modulus (E): 2.6E+7 N/m2
- Poisson’s ratio (ν): 0.2
- Solid density (ρs): 2000 Kg/m3
- Fluid density (ρf): 1000 Kg/m3
- Porosity (φ): 0.3
- Solid bulk modulus (Ks): 1.0E+10 N/m2
- Fluid bulk modulus (Kf): 2.0E+7 N/m2
- Transversal permeability (kn): 1.0E-11 m2
- Dynamic viscosity (μ): 0.001 s·N/m2
- Damage threshold (ϱy): 0.001
- Minimum joint width (tmin): 0.002 m
- Critical displacement (δc): 1.0E-4 m
- Yield stress (σy): 1.0 N/m2
- Friction coefficient (μF): 0.4
Results
The next two figures show the displacement and the pore pressure fields at time t = 0.001 s.
References
[1] I. de Pouplana and E. Oñate. Finite element modelling of fracture propagation in saturated media using quasi-zero-thickness interface elements. Computers and Geotechnics, 2017, http://dx.doi.org/10.1016/j.compgeo.2017.10.016.