TWO-PHASE FLOWS IN OPEN GEOLOGICAL FRACTURES: A COMBINED EXPERIMENTAL AND NUMERICAL INVESTIGATION
M.Sc. Rahul Krishna, Prof. Dr. Insa Neuweiler, Yves Méheust, PhD HdR
Many geotechnical and environmental engineering problems, such as geothermal energy production or storage of fluids in deep formations, involve flow processes in subsurface fractured media. When two immiscible fluids coexist, the flow involves the displacement of the interfaces between them. This so-called two-phase flow can result in very complex and intricate spatial distributions of the fluids, depending on the mean flow velocity, the viscosities and densities of the fluids, the mechanical properties of their interface, and the geometry of the permeable medium. For porous media, the rich phenomenology of two-phase flows has been investigated at length in the last 20 years. In geological fractures, on the contrary, the characterization of this rich phenomenology is still in its infancy. The objective of this project is to systematically investigate it, as a function of the fluids’ properties, flow conditions, as well as fracture geometry and closure.
This is done through a combination of (i) laboratory experiments on transparent setups reproducing a realistic fracture geometry but allowing for measurements of the spatial distributions of the two fluids and their velocities, and (ii) numerical simulations of the two-phase flow in the fracture space, based on the first principles of fluid mechanics. The laboratory experiments will be set up and run at Géosciences Rennes, while the numerical study will be developed and run at the Institute of Fluid Mechanics and Environmental Physics (ISU), thus building on the complementary expertise of the two groups.
Last Change: 24.05.24
