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Simplified versus Detailed Two-Dimensional Approaches to Transient Flow Modeling in Urban Areas |
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| Authors: | G Petaccia S Soares-Fraz?o F Savi L Natale Y Zech |
| Affiliation: | 1Professor Assistant, Dept. of Hydraulic and Environmental Engineering, Univ. of Pavia, Via Ferrata 1, 27100 Pavia, Italy (corresponding author). E-mail: petaccia@unipv.it 2Research Associate, Fond de la Recherche Scientifique FNRS; and, Dept. of Civil and Environmental Engineering, Hydraulics Unit, Université Catholique de Louvain, Place du Levant 1, B-1348 Louvain-la-Neuve, Belgium. 3Deceased December 24, 2009; formerly, Professor, Dept. of Hydraulic and Transportation and Highways, Univ. of Rome “La Sapienza,” Via Eudossiana 18, 00184 Roma, Italy. 4Professor, Dept. of Hydraulic and Environmental Engineering, Univ. of Pavia, Via Ferrata 1, 27100 Pavia, Italy. 5Professor, Dept. of Civil and Environmental Engineering, Hydraulics Unit, Université Catholique de Louvain, Place du Levant, 1, B-1348 Louvain-la-Neuve, Belgium. |
| Abstract: | Simplified and detailed two-dimensional modeling approaches to transient flows in urban areas, based on finite-volume solution of the shallow water equations, are compared. Through the example of a dam-break flow in a simplified urban district for which accurate laboratory data exist, various methods are compared: (1) the solution of the two-dimensional shallow water equations with a detailed meshing of each street; (2) the use of a porosity concept to represent the reduction of water-storage and conveyance in the urban area; and (3) the representation of urban areas as zones with higher friction coefficient. Accuracy and adequacy of each method are assessed through comparison with the experiments. Among the simplified models, the porosity approach seems to be the most adequate as head losses at the entrance and the exit of the city are considered. |
| Keywords: | Shallow water Urban areas Dam failures Hydraulic roughness Porosity Transient flow |