Search results for "dimensional analysi"
showing 8 items of 68 documents
A new empirical model for estimating calanchi Erosion in Sicily, Italy
2015
Abstract Calanchi (plural of calanco) are typical badland landforms of the Italian landscape. They consist of dense networks of V-shaped valleys, with a sparse or absent vegetation cover, which frequently develop on unconsolidated or poorly consolidated clayey deposits. In this paper, the dimensional analysis and the incomplete self-similarity theory were used to deduce a model relating the volume of sediments eroded from the calanchi area to a set of geometric attributes of their tributary areas. The morphometric characteristics of 209 calanchi basins were used to calibrate and validate the model. The predictive skill of the model was assessed by calculating the mean square error and the N…
A full‐scale study of Darcy‐Weisbach friction factor for channels vegetated by riparian species
2021
In this article, an open channel flow resistance equation, deduced applying dimensional analysis and incomplete self-similarity condition for the flow velocity distribution, was tested using measurements carried out in a full-scale channel equipped with three types of riparian plants (Salix alba L., Salix caprea L. and Alnus glutinosa L.). In the experimental channel, having banks lined with boulders, the vegetation branches were anchored in a concrete bottom. For each species, the measurements were carried out with plants having different amounts of leaves, different plant density and plant area index. The relationship between the scale factor Γ of the velocity profile and the Froude numbe…
Closure to "Assessing stage-discharge relationships for circular overflow structure" by M. Bijankhan and V. ferro
2018
The paper is a closure to a previous article.
Discussion of “Three Simple Flumes for Flow Measurement in Open Channels” by Zohrab Samani
2018
In this paper the results on three simple flumes for flow measurements are discussed.
Simple flume with a central baffle
2016
Abstract In this paper the stage-discharge relationship of a flume with a central baffle is theoretically deduced using the Buckingham-Theorem of the dimensional analysis and the self-similarity theory. The new stage-discharge equation is calibrated by the measurements carried out by Peruginelli and Bonacci using a baffle having a given throat length and five different values of the contraction ratio. Finally, for a given throat length, a relationship linking the discharge with the upstream water depth, the contraction ratio and the contracted width is deduced.
New Stage–Discharge Relationship for Triangular Broad-Crested Weirs
2022
Simple hydraulic structures, such as weirs, allow measuring flow discharge by using the upstream flow depth and a stage–discharge relationship. In this relationship, a discharge coefficient is introduced to correct all the effects neglected in the derivation (viscosity, surface tension, velocity head in the approach channel, flow turbulence, non-uniform velocity profile, and streamline curvature due to weir contraction). In this paper, the dimensional analysis and the incomplete self-similarity theory are used to investigate the outflow process of triangular broad-crested weirs, characterized by different values of the ratio between crest height p and channel width B, and to theoretic…
Comment on "Measuring the flow resistance of submerged grass"
2004
In this short note, the experimental data of Wilson and Horritt (2002.Hydrological Processes16: 2589–2598), jointlywith the measurements by Kouwenet al. (1969.Journal of Irrigation and Drainage Division, ASCE95: 329–342)and by Raffaelliet al. (2002 InProceedings XXVIII Convegno di Idraulica e Costruzioni Idrauliche, Cosenza, Italy;223–230), arefirstly used to test Kouwen’s approach. All experimental data are then used to calibrate aflow resistanceequation that was theoretically deduced by dimensional analysis and self-similarity theory
Morphometric analysis of two calanchi areas in Sicily (Italy) by exploiting high resolution Digital Elevation Models
2013
In the Mediterranean areas, specifically in Sicily (Italy), irregular rainfalls, strong seasonal changes, scarce vegetation cover and, frequently, outcropping of clayey deposits favor water erosion phenomena. Badland landscapes are the result of severe erosion processes, characterized by steep slopes, sparse vegetation, high drainage density, rapid erosion rates and a shallow or non existing regolith profile. In this investigation we focused on the calanchi badland type, consisting of heavily dissected terrain with steep, unvegetated slopes and channels that rapidly incise and extend headwards. This research was carried out in two calanchi sites located in Sicily. The geometry of 25 badland…