Gabriella Petaccia
University of Pavia
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Featured researches published by Gabriella Petaccia.
Natural Hazards | 2015
Pierfranco Costabile; Francesco Macchione; L. Natale; Gabriella Petaccia
Nowadays, the use of 2-D fully dynamic models represents the most reliable approach for flood inundation and flood hazard studies, especially in complex applications. However, 1-D modeling is still a widely used approach due to the reduced computational time and cost. The introduction of LIDAR technique has stimulated a more detailed topographic description of river reaches. As a result, this huge amount of topographic data can lead to significant improvements in the 1-D computations. Therefore, the main purpose of this paper is to realize how the improvements in the topographic description can reduce the difference between 1-D and 2-D models, highlighting at the same time the critical aspects and the limitations of 1-D approach in the hydraulic simulation as well as in the spatial representation of the results. The analysis presented in the paper refers to two actual case studies for which terrestrial and airborne LIDAR DEMs were collected on purpose. The results of those applications show that the use of 1-D models requires a greater hydraulic skilfulness than the use of 2-D model.
Journal of Hydraulic Engineering | 2010
Gabriella Petaccia; Sandra Soares-Frazão; Fabrizio Savi; L. Natale; Yves Zech
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.
Computational Geosciences | 2016
Gabriella Petaccia; F. Leporati; E. Torti
This paper presents two 2D dam break parallelized models based on shallow water equations (SWE) written in conservative form. The models were implemented exploiting multicore PC systems and graphics processor unit (GPU) architectures under the OpenMP and the NVIDIA™’s compute unified device architecture (CUDA) frameworks. The mathematical model is solved using a finite-volume technique on an unstructured grid, with Roe’s approximate Riemann solver, a first-order upwind scheme. The upwind treatment of the source terms is implemented. A technique to cope with a wetting-drying advance front is adopted, together with the inclusion of the influence of source terms in the stability constraint in order to prevent negative water depths at the dry fronts. The proposed model is first applied to a laboratory test and then to a real dam break that occurred in Italy in 1935. Results on different grid sizes are compared to show the computing efficiency between the original sequential model and the parallelized models.
Natural Hazards | 2017
Elisabetta Persi; Gabriella Petaccia; Stefano Sibilla
The paper discusses a model which predicts the trajectory of floating rigid bodies and may be applied to compute the motion of woody “debris” mobilized during floods. The model couples a Discrete Element (DE) Lagrangian approach for the calculation of motion of rigid bodies with the Eulerian solution of the shallow water equations (SWE), in order to simulate the transport of a cylinder in a two-dimensional stream. It differs from existing models since it is based on a dynamic approach, adapting the Basset–Boussinesq–Oseen equation. In a first step, forces are computed from flow and log velocities; then, the equations of dynamics are solved to model the planar roto-translation of the body. Model results and physical reliability are clearly affected by the values of the drag and side coefficients, especially since logs, modelled as cylinders, are able to change their orientation towards the flow. Experimental studies to evaluate drag and side coefficients can be found in the literature for a submerged cylinder, with various orientations. To extend such results to the case of a floating log, the authors performed a series of laboratory tests on partially submerged cylinders, implementing the outcomes in the proposed DE-SWE model. The coupled model is validated against existing laboratory data concerning spheres and wooden cylinder transport.
Natural Hazards and Earth System Sciences | 2012
Ignacio Escuder-Bueno; Jesica Tamara Castillo-Rodríguez; S. Zechner; C. Jöbstl; Sara Perales-Momparler; Gabriella Petaccia
Journal of Hydroinformatics | 2013
Gabriella Petaccia; L. Natale; Fabrizio Savi; Mirjana Velickovic; Yves Zech; Sandra Soares-Frazão
Applied Mathematical Modelling | 2016
Mario Morales-Hernández; Gabriella Petaccia; P. Brufau; P. García-Navarro
Archive | 2014
Pierfranco Costabile; Francesco Macchione; Gabriella Petaccia; L. Natale
Archive | 2013
Gabriella Petaccia
Integrating water systems. Proceedings of the Tenth International Conference on Computing and Control for the Water Industry, CCWI 2009 - 'Integrating Water Systems', Sheffield, UK, 1-3 September 2009. | 2010
B. Latorre; J. Burguete; J. Murillo; P. Brufau; P. García-Navarro; Gabriella Petaccia; B. Calvo; Fabrizio Savi; J. Boxall; C. Maksimovic