Depth integrated equations applied to longitudinal discontinuities on the channel bed

Download
2015
Razmand, Maral
Depth integrated equations can be solved over large domains to provide flood inundation maps. In urban and rural areas however, there may be numerous natural or artificial bottom boundary discontinuities in the form of rapid variations in the bed elevation. Such discontinuities cause abrupt changes in the source terms of the governing equations and can significantly affect stability and accuracy of the numerical solution. A 1D code is developed for shallow water equations using HLL approximate Riemann solver. It is applied to a dam-break case until the steady state is reached between two end boundaries and volume conserving boundary conditions has been searched. Channel beds with step-like discontinuities were also studied. It is found that bed slopes greater than 1 can cause spurious water surface oscillations in the numerical solution.

Suggestions

Assessment of sensitivity of depth integrated solutions to longitudinal discontinuities on the channel bed
Mohammadi, Ramez; Aydın, İsmail; Department of Civil Engineering (2019)
Depth integrated equations can be easily solved over large domains to provide flood inundation maps. In urban and rural areas however, there may be numerous natural or artificial bottom boundary discontinuities in the form of rapid variations in bed elevation. Such discontinuities cause abrupt changes in the source terms of the governing equations and can significantly affect stability and accuracy of the numerical solution. This study concentrates on the assessment of sensitivity of the governing equations...
Water surface profile computation around square blocks by imaginary representation of the obstructions in the shallow water equations
Hofioni, Sayed Omar; Aydın, İsmail; Department of Civil Engineering (2021-7)
Depth integrated shallow flow equations can be solved easily over large domains to provide flood inundation maps. However, there may be numerous natural or artificial obstructions that increase resistance to flow due to drag forces induced on the submerged volumes. It is possible to numerically solve the governing equations on a suitable grid system for the flow field around such obstructions and determine the flow depths. But, when the number of obstructions increases with arbitrary size and distribution, ...
1-D and 2-D flood modeling studies and upstream structural measures for Samsun city Terme district
Bozoğlu, Başar; Akyürek, Sevda Zuhal; Department of Civil Engineering (2015)
In this study, Samsun City Terme District flood problem is examined with 1-D and 2-D flood modeling approach. In July 2012 Terme City Centre was exposed to a flood event. Approximately 510 m³/s flood discharge passed through the city. The river water level reachedtop of the levees and some parts were overflowed. The area is exposed to flooding as ifthe other urban areas located in Black Sea Region. The possible causes and effects of the flood problem on the Terme District are examined and some upstream stru...
Structure preserving model order reduction of shallow water equations
Karasözen, Bülent; UZUNCA, MURAT (2020-07-01)
In this paper, we present two different approaches for constructing reduced-order models (ROMs) for the two-dimensional shallow water equation (SWE). The first one is based on the noncanonical Hamiltonian/Poisson form of the SWE. After integration in time by the fully implicit average vector field method, ROMs are constructed with proper orthogonal decomposition(POD)/discrete empirical interpolation method that preserves the Hamiltonian structure. In the second approach, the SWE as a partial differential eq...
Broadband Analysis of Multiscale Electromagnetic Problems: Novel Incomplete-Leaf MLFMA for Potential Integral Equations
Khalichi, Bahram; Ergül, Özgür Salih; Takrimi, Manouchehr; Erturk, Vakur B. (2021-12-01)
Recently introduced incomplete tree structures for the magnetic-field integral equation are modified and used in conjunction with the mixed-form multilevel fast multipole algorithm (MLFMA) to employ a novel broadband incomplete-leaf MLFMA (IL-MLFMA) to the solution of potential integral equations (PIEs) for scattering/radiation from multiscale open and closed surfaces. This population-based algorithm deploys a nonuniform clustering that enables to use deep levels safely and, when necessary, without compromi...
Citation Formats
M. Razmand, “Depth integrated equations applied to longitudinal discontinuities on the channel bed,” M.S. - Master of Science, Middle East Technical University, 2015.