INTERNATIONAL COLLABORATION: ESTABLISHING A POROUS MEDIA OBSERVATIONAL FACILITY AT THE UNIVERSITY OF KASSEL, GERMANY

PI: C. Welty, Co-PI: Tissa Illangasekare, Colorado School of Mines
Project Duration: 4/1/98 - 3/31/00
Funding Source: NSF Office of International Programs
Funding Amount: $15,500

Objectives

The principal objective of this research was to design and construct, at the University of Kassel in Germany, a large-scale (10-m) experimental vessel containing structured porous media with measurable statistical properties comparable to that of a scaled, heterogeneous sand and gravel aquifer, and to use this vessel for observations of fluid flow and mass transport under controlled conditions. This kind of apparatus can contribute to improving prediction of aquifer contamination by comparison of observational results with stochastic and other mathematical models of a number of non-ideal contaminant transport processes. Virtually any fluid dynamics problem in porous media can be studied in detail in the proposed vessel. Of current interest to the PIs are the areas of: (1) dense, miscible fluid transport; (2) virus and colloid transport, (3) immiscible fluid flow, all of which are environmental problems for which widely-accepted, accurate predictive methods for transport in heterogeneous porous media are not currently available.

The work represented and international collaboration between the United States and Germany. The Department of Geohydraulics and Engineering Hydrology at University of Kassel funded construction of the proposed porous media facility to complement the extensive surface-water hydraulics equipment in its Wasserbauer Laboratory. The U.S. side contributed expertise to design of the facility. The scope of this project was to design and install the tank and carry out a set of runs for the density-coupled, miscible-displacement problem.

The purpose of the funds from NSF's Office of International Programs was to support travel of the PI and Co-PI to the project site to provide expertise as needed. These funds were used to partly pay for the costs of C. Welty's living sabbatical living expenses in 1998, and to cover the cost of return visits of C. Welty and of visits to the project site by T. Illangasekare twice per year. C. Welty was on site from 11/97 - 9/98 and has returned for visits in 2/99, 4/99, and 7/99. T. Illangasekare visited the project in 6/98, 4/99, and 7/99.

Project Accomplishments

Tank construction began in October 1997. Blueprints were drawn up by Dipl. Ing. Ralf Feldner, Lab Technician, based upon information provided by C. Welty and T. Illangasekare on T.Illangasekare's facilities in Colorado. Construction was supervised by R. Feldner in consultation with C. Welty and T. Illangasekare, and carried out principally by undergraduate students Axel Waldhoff and Tobias Wunschik, and later with the help of Matthias Hensel. The students were paid as part-time hourly workers. Tank and appurtenance construction were completed in December 1998. Packing of the tank as a correlated random field was carried out in April 1999 and supervised by Bernd Krüger. The first experimental run of the density-coupled experiments was started in July 1999. Due to lack of adequate resources available in Kassel to complete the experiments in the designated project period, the experiments are being continued in the U.S. under funding from NSF's Hydrologic Science program.

A photo album of the progress of the tank construction is available for viewing here.

Related presentations and publications

Welty, C., and M.M. Elsner, M., Construction of Random Fields in the Laboratory for Observations of Fluid Flow and Mass Transport, J.Hydrology, 202(1/4), 192-211, 1997.

Welty, C. "Design and Construction of a 10-m Tank Containing Porous Media Packed as a Correlated Random Field for Observations of Density-Coupled Transport", EOS Trans. AGU, 78(46), Fall Meeting Suppl., S272, 1997.