Developing Darcian Means to Correct Order-of-Magnitude Subsurface Flow Errors in Models

30 Developing Darcian Means to Correct Order-of-Magnitude Subsurface Flow Errors in Models--Aquarius Engineering, 1700 Ross Avenue, Springdale, AR 72762-3034; (501) 872-1657 Dr. Donald L. Baker, Principal Investigator Dr. Donald L. Baker, Business Official DOE Grant No. DE-FG02-97ER82329 Amount: $72,104 Recent publications show that standard approximations of flow at nuclear and chemical waste sites can be off by orders of magnitude, directly affecting the accuracies of calculated flow, and thus the transport of contaminants. This kind of error has the potential of rendering many current predictions of the environmental threat from chemicals and radioactive materials in unsaturated and possibly multi-flow conditions to be wrong. A new approach to this issue performs calculations exactly, but requires excessive computer time. This project seeks to find computationally-efficient methods to calculate or approximate exact means in running models. Phase I work will investigate generating approximations for exact means using surface fitting with parametric equations, interpolation and digital morphing methods on a high-speed workstation. It will apply any results to 2-D problems of fracture flow and capillary barriers, and validate new concepts with existing experimental data in running models. Phase II work will develop any experimental tests and equipment identified in Phase I needed to further validate the concepts, and develop a user-friendly model to be used by consulting and regulating interests on Pentium or DEC-Alpha machines. It will also extend the concepts to multi-phase flow, if time permits. Commercial Applications and Other Benefits as described by the awardee: Success should provide up to an order of magnitude of improvement in computational accuracy and/or efficiency for models of unsaturated flow for hazardous waste consultants and regulators. Other possible applications include composite material processes, such as quality and property control of metal-wetted ceramics, or flow through environmental filter media in microgravity conditions.