Multiphase flow in complex fracture apertures under a wide range of flow conditions

摘要

The primary purpose of this project is to use a combination of computer modeling and laboratory experiments to obtain a better understanding of multiphase flow in geometrically complex fracture apertures under a wide range of flow conditions. Because most traditional grid-based numeral methods perform poorly for multiphase flows with complex dynamic interfaces due to problems such as artificial interface broadening, grid entanglement, loss or gain of mass and their inability to handle fluid-fluid-solid contact line dynamics, the modeling component of the program relies primarily on particle based methods. In particle based models, the fluid-fluid interfaces move as the particles representing the fluids move--there is no need for explicit interface tracking, and no artificial front broadening. In addition, the fluid-fluid-solid contact line dynamics is also handled automatically by adjusting the interactions between the fluid particles and the particles used to represent solid boundaries. However, it can be difficult to select fluid-particle/solid-particle interactions that reproduce the wetting behaviors observed in experimental or natural systems. Because, different model approaches have characteristic strengths and weaknesses, three different classes of particle-based models (lattice Boltzmann, dissipative particle dynamics and smoothed particle hydrodynamics) are being employed in this program. This will allow us to achieve our objective of simulating multiphase flow under a wide range of flow conditions for a wide range of fluid properties.