Regensburg 2019 – wissenschaftliches Programm
CPP 25.56: Poster
Dienstag, 2. April 2019, 14:00–16:00, Poster B1
Monitoring Pressure Fluctuations in Artificial Porous Media. — •Michael Jung1,2, Martin Brinkmann1, Stephan Herminghaus2, and Ralf Seemann1,2 — 1Universität des Saarlandes, Saarbrücken, Germany — 2Max Planck-Institute for Dynamics and Self-Organization, Göttingen, Germany
We aim to understand the microscopic mechanisms of individual capillary instabilities which govern slow displacement processes in permeable porous media. Therefore we investigate the influence of the pore space geometry and wettability on the landscape of pressure variations during slow displacement of fluid from an arrangement of glass beads by a second, immiscible fluid. For an experimental verification of the capillary pressure variations, we measure the pressure of a bursting meniscus in a single throat formed by three beads. Different wettability of the glass beads is realized by wet-silanization techniques as OTS (octadecyltrichlorosilane) or APTES (3-aminopropyltriethoxysilane)-coating which result in a water-air contact angle on glass beads of 110° and 60°, respectively. Heterogeneous wettability is achieved by throats assembled from beads with different coatings. The experiments shall be compared with numerical calculations of the capillary pressure in such a heterogeneous throat for various combination of contact angles. Understanding the characteristic pressure variations of single throats, we will extend our setup to small bead-packs consisting of a few layers of glass beads with heterogeneous wettability.