| Abstract: | Past applications of one-dimensional advection, dispersion, and transient storage zone models have almost exclusively relied on a central differencing, Eulerian numerical approximation to the nonconservative form of the fundamental equation. However, there are scenarios where this approach generates unacceptable error. A new numerical scheme for this type of modeling is presented here that is based on tracking Lagrangian control volumes across a fixed (Eulerian) grid. Numerical tests are used to provide a direct comparison of the new scheme versus nonconservative Eulerian numerical methods, in terms of both accuracy and mass conservation. Key characteristics of systems for which the Lagrangian scheme performs better than the Eulerian scheme include: nonuniform flow fields, steep gradient plume fronts, and pulse and steady point source loadings in advection-dominated systems. A new analytical derivation is presented that provides insight into the loss of mass conservation in the nonconservative Eulerian scheme. This derivation shows that loss of mass conservation in the vicinity of spatial flow changes is directly proportional to the lateral inflow rate and the change in stream concentration due to the inflow. While the nonconservative Eulerian scheme has clearly worked well for past published applications, it is important for users to be aware of the scheme‘s limitations. ?? 2008 ASCE. |
| Genre: | Article |
| ProdID: | 70033100 |
| Citation Author: | Cox, T. J.; Runkel, R. L. |
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| Citation End Page: | 1005 |
| Citation Issue: | 12 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Environmental Engineering |
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| Citation Number Of Pages: | 10 |
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| Citation Search Results Text: | Eulerian-Lagrangian numerical scheme for simulating advection, dispersion, and transient storage in streams and a comparison of numerical methods; 2008; Article; Journal; Journal of Environmental Engineering; Cox, T. J.; Runkel, R. L. |
| Citation Start Page: | 996 |
| Citation Volume: | 134 |
| Citation Year: | 2008 |
| Type: | citation/reference |
| Text: | Eulerian-Lagrangian numerical scheme for simulating advection, dispersion, and transient storage in streams and a comparison of numerical methods; 2008; Article; Journal; Journal of Environmental Engineering; Cox, T. J.; Runkel, R. L. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1061/(ASCE)0733-9372(2008)134:12 |
| Date Other: | Tue, 1 Jan 2008 00:00 -0600 |
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