Search results for " hydraulic model"
showing 8 items of 8 documents
Hydraulic Models and Finite Elements for Monitoring of an Earth Dam, by Using GNSS Techniques
2016
This work gives a comparison between different mathematicalmodels for the evaluation of the movements of an earthendam situated between Bivona and Alessandria della Rocca, inthe province of Agrigento (AG), Italy. The models selected areof a hydraulic nature, already tested on concrete dams, andfinite elements models which, on the contrary, exploit geotechnicalparameters. The results obtained from the comparisonof the displacement planimetric components and the relativetime series of data over a period of two years appear to befully satisfactory, in fact using both models of a hydraulic andgeotechnical nature, we reach residues of just mm. To supportthis work, a monitoring procedure using GN…
ASSESSMENT OF RIVER FLOW WITH SIGNIFICANT LATERAL INFLOW THROUGH REVERSE ROUTING MODELING
2017
The discharge hydrograph estimation in rivers based on reverse routing modeling and using only water level data at two gauged sections is here extended to the most general case of significant lateral flow contribution, without needing to deploy rainfall-runoff procedures. The proposed methodology solves the Saint-Venant equations in diffusive form also involving the lateral contribution using an ‘head driven’ modeling approach where lateral inflow is assumed to be function of the water level at the tributary junction. The procedure allows to assess the discharge hydrograph at ends of a selected river reach with significant lateral inflow, starting from the stage recorded there and without n…
On the use of innovative post-event data for reducing uncertainty in calibrating flood propagation models
2013
Hydraulic models for flood propagation description are an essential tool in many fields and are used, for example, for flood hazard and risk assessments, evaluation of flood control measures, etc. However, the calibration of these models is still underdeveloped in contrast to other models like e.g. hydrological models essentially for lacking of specific data, because extreme flood events occur rarely and very rarely are monitored. Very often calibration data, when available, consist of water depths measure in some scattered points. For an inundation event occurred on November 2011 in Sicily, new sources of data were available due to the availability of many videos recorded by ‘common’ peopl…
Numerical and experimental investigation of a cross-flow water turbine
2016
ABSTRACTA numerical and experimental study was carried out for validation of a previously proposed design criterion for a cross-flow turbine and a new semi-empirical formula linking inlet velocity to inlet pressure. An experimental test stand was designed to conduct a series of experiments and to measure the efficiency of the turbine designed based on the proposed criterion. The experimental efficiency was compared to that from numerical simulations performed using a RANS model with a shear stress transport (SST) turbulence closure. The proposed semi-empirical velocity formula was also validated against the numerical solutions for cross-flow turbines with different geometries and boundary c…
Discharge estimation in natural channels with significant lateral inflow
2015
The indirect measurement technique for discharge estimation, based on water level data analysis in two different river sections, is extended to the case of existing significant tributary flow between the two sections. The methodology is based on the calibration of a numerical flow routing algorithm, solving the Saint-Venant equations in diffusive form along the main channel between the two measurement sections. The first calibration parameter is the average Manning's roughness coefficient holding in the main channel, the other ones are relative to the rating curve of each tributary channel, estimated per unit roughness coefficient and per unit slope immediately before the junction of the tr…
PUMP AS TURBINE (PAT) IN INTERMITTENT DISTRIBUTION NETWORKS
2012
A hydraulic model was performed in order to evaluate potential energy recovery resulting by the use of centrifugal pump as turbines (PAT) in the water distribution network characterized by the presence of private tanks. The model integrates the Enhanced Global Gradient Algorithm (EGGA) (Todini [1], Giustolisi et al. [2]), with a pressure driven model (Criminisi et al. [3]) that entails a more realistic representation of the influence of the private tanks filling and emptying process in the network behaviour. The model was applied to real case study: a district metered area in Palermo (Italy). Namely three different scenarios were analyzed and compared with the actual scenario (Scenario 0 - …
Discharge estimation combining flow routing and occasional measurements of velocity
2011
A new procedure is proposed for estimating river discharge hydrographs during flood events, using only water level data at a single gauged site, as well as 1-D shallow water modelling and occasional maximum surface flow velocity measurements. One-dimensional diffusive hydraulic model is used for routing the recorded stage hydrograph in the channel reach considering zero-diffusion downstream boundary condition. Based on synthetic tests concerning a broad prismatic channel, the “suitable” reach length is chosen in order to minimize the effect of the approximated downstream boundary condition on the estimation of the upstream discharge hydrograph. The Manning’s roughness coefficient is calibra…
Urban Flood Prediction through GIS-Based Dual-Coupled Hydraulic Models
2022
Propagation of pluvial floods in urban areas, occurring with return time periods of few years, can be well solved using dual models accounting for the mutual relationship between the water level in the streets and the discharges inside the sewer pipes. The extended WEC-flood model (EWEC), based on the use of unstructured triangular meshes and a diffusive formulation of the momentum equations in both the 2D and the 1D lower domains, is presented along with its novelty, limits, and advantages. The model is then applied to a small computational domain in the Palermo area, where only some ‘hard’ data given by one rain gauge has been used for calibration and validation, along with ot…