D. Logashenko

Optimal Geometrical Design of Bingham Parameter Measurement Devices

Usually, Bingham material parameters are determined in a rather cumbersome and time consuming manner. Recently, automatic numerical parameter identification techniques for Bingham fluids have been developed. Here, a method is presented to compute optimal shapes of corresponding measurement devices which lead to a high reliability of the resulting parameter estimation.

Numerical methods for flow in fractured porous media

We present a numerical technique for the simulation of salinity- as well as thermohaline-driven flows in fractured porous media. In this technique, the fractures are represented by low-dimensional manifolds, on which a low-dimensional variant of the PDEs of variable-density flow is formulated. The latter is obtained from the full-dimensional model by the average-along-the-vertical. The discretization of the resulting coupled system of the full- and low-dimensional PDEs is based on a finite-volume method. This requires a special construction of the discretization grid which can be obtained by the algorithm presented in this work. This technique allows to reconstruct in particular the jumps of the solution at the fracture. Its precision is demonstrated in the numerical comparisons with the results obtained in the simulations where the fractures are represented by the full-dimensional subdomains.

Preparation of grids for simulations of groundwater flow in fractured porous media

This work presents an extension of grid generation techniques for finite-volume discretizations of density-driven flow in fractured porous media, in which fractures are considered as low-dimensional manifolds and are resolved by sides of grid elements. The proposed technique introduces additional degrees of freedom for the unknowns assigned to the fractures and thus allows to reconstruct jumps of the solution over a fracture. Through the concept of degenerated elements, the proposed technique can be used for arbitrary junctions of fractures but is sufficiently simple regarding the implementation and allows for the application of conventional numerical solvers. Numerical experiments presented at the end of the paper demonstrate the applicability of this technique in two and three dimensions for complicated fracture networks.

Forchheimer’s correction in modelling flow and transport in fractured porous media

The scope of this manuscript is to investigate the role of the Forchheimer correction in the description of variable-density flow in fractured porous media. A fractured porous medium, which shall be also referred to as “the embedding medium”, represents a flow region that is made macroscopically heterogeneous by the presence of fractures. Fractures are assumed to be filled with a porous medium characterized by flow properties that differ appreciably from those of the embedding medium. The fluid, which is free to move in the pore space of the entire flow region, is a mixture of water and brine. Flow is assumed to be a consequence of the variability of the fluid mass density in response to the generally nonuniform distribution of brine, which is subject to diffusion and convection. The fractures are assumed to be thin in comparison with the characteristic sizes of the embedding medium. Within this framework, some benchmark problems are solved by adopting two approaches: (i) the fractures are treated as thin but

FAST NUMERICAL INTEGRATION FOR SIMULATION OF STRUCTURED POPULATION EQUATIONS

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Flux-based level-set method for two-phase flows on unstructured grids

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Simulation of density-driven flow in fractured porous media

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