Hydraulics & Waterways

Oral

397239 - Modeling internal erosion processes in soil pipes; capturing changing geometry dynamics

Tuesday, June 5
10:30 AM - 12:00 PM
Location: Regency Room
Co-Authors: Glenn Wilson, Oxford, MS – USDA-ARS; Garey Fox, Raleigh, NC – North Carolina State University

Subsurface erosion and the formation of soil pipes adversely affects the stability of dams, levees, and hillslopes. Using COMSOL-MP as the computational platform we modeled the instantaneous internal erosion of a soil pipe by numerical solution of the Navier-Stokes equations coupled with a turbulence model, and the convection-dispersion equation to solve for the transport of eroded sediment particles. The erosion rate from the pipe wall is modeled using the well-known excess shear equation. The instantaneous erosion rates derived from these solutions were found to compare well with the measured erosion rates derived from laboratory soil pipe erosion experiments. The greatest limitation of these numerical solutions is that they are for the case of stationary geometry for the soil pipe, while in the laboratory experiments, and in field conditions the geometry of an eroding soil pipe changes as erosion progresses. Currently we are working on expanding the modeling capability to facilitate the simulation of soil pipe geometry dynamics. Two approaches are being pursued. One approach treats the solution as being composed of a series of quasi-steady steps of flow and erosion, where within each step the pipe geometry is treated as being fixed. The geometry within the given step is then adjusted to account for the calculated erosion in preparation for the subsequent step. The second approach involves modeling the dynamic geometry directly using a moving boundary and solution domain adjustment procedure. The results from these two modeling approaches will be compared to each other, and to experimental results.

John L. Nieber, PhD, P.E., P.H.

Professor
Department of Bioproducts and Biosystems Engineering

John L. Nieber, Ph.D., P.E., P.H., Professor, Department of Bioproducts and Biosystems Engineering, University of Minnesota

A native of Upstate New York he received his B.S. degree in Forest Engineering at Syracuse University in 1972, his M.S. degree in Civil and Environmental Engineering at Cornell University in 1974, and his Ph.D. in Agricultural Engineering at Cornell University in 1979. He joined the Department of Agricultural Engineering at Texas A&M University as an Assistant Professor in 1979. He left Texas A&M in 1985 to join the Department of Agricultural Engineering at the University of Minnesota as an Associate Professor, and in 1995 he was promoted to Full Professor at Minnesota in the department which is now called Bioproducts and Biosystems Engineering.

John’s research interests involve hydrologic process discovery and modeling, and flow and transport processes in porous media. He is a member of the American Society of Agricultural and Biological Engineers, American Geophysical Union, and a certified Professional Hydrologist with the American Institute of Hydrology.

Presentation(s):

Send Email for John Nieber

Glenn V. Wilson, PhD

Research Hydrologist
USDA-ARS

Presentation(s):

Send Email for Glenn Wilson

Garey Alton. Fox, Ph.D., P.E., D.WRE

Professor and Department Head
North Carolina State University

Presentation(s):

Send Email for Garey Fox


Assets

397239 - Modeling internal erosion processes in soil pipes; capturing changing geometry dynamics



Attendees who have favorited this

Please enter your access key

The asset you are trying to access is locked. Please enter your access key to unlock.

Send Email for Modeling internal erosion processes in soil pipes; capturing changing geometry dynamics