Search results for " Dimensional analysis"

Closure to "Deducing a drain spacing formula by applying dimensional analysis and self-similarity theory" by Vito Ferro

2017

This paper is a closure of the discussions to the paper "Deducing a drain spacing formula by applying dimensional analysis and self-similarity theory"

Closure "Stage-discharge relationship for an upstteam inclined grid with transversal bars"

2016

The paper is a closure of “Stage-Discharge Relationship for an Unpstream Inclined Grid with Transversal Bars”

Generalised stage-discharge relationship for rectangular weirs

2018

Rectangular weirs, which are very common hydraulic structures used in irrigation channels as water measuring devices, can be used for measuring very small discharges as well as high flow rates. From the practical point of view the availability of a unique stage-discharge formula that can be applied for the different types of the rectangular weirs would be of great practical importance. At first, in this paper the Buckingham’s Theorem of the dimensional analysis and the self-similarity theory are used to deduce the stage-discharge curve of different kinds of rectangular weirs such as slit and partially contracted ones. Then the proposed formula is calibrated using both the experimental data …

Closure to “Experimental Study of the Stage-Discharge Relationship for an Upstream Inclined Grid with Longitudinal Bars” by C. Di Stefano and V. Ferro

2014

The discusser would like to thank the authors of the original paper for investigating the outflow process of an upstream inclined grid with longitudinal bars using the dimensional analysis and the incomplete self-similarity theory. The discusser, however, would like to add a few points. Using the theoretical analysis the authors of the original paper showed that a power equation can be used for establishing the stage-discharge equation of an upstream inclined grid with longitudinal bars. The authors of the original paper also showed that the coefficient and exponent of the power equation depend on the slope angle and the void ratio. They proposed a stage-discharge equation

Water erosion assessment and modeling in two calanchi areas in Sicily, Italy

I badlands sono forme di erosione localizzate principalmente nelle regioni aride e semi-aride e sono formati da una complessa combinazione di processi morfogenetici. La loro origine coinvolge processi di erosione idrica ma anche tunnel erosion e movimenti di massa. Inoltre, tali forme possono anche essere correlate a fenomeni di erosione accelerata che hanno luogo laddove le azioni antropiche disturbano l'equilibrio naturale tra processi morfogenetici e suolo. I badlands, con i loro versanti ripidi, sono spesso inseriti all’interno di paesaggi più dolci, in mezzo a colture o bosco, localizzati in aree dove i processi responsabili del loro modellamento sono di solito piuttosto attivi determi…

Deducing a Drain Spacing Formula by Applying Dimensional Analysis and Self-Similarity Theory

2016

For designing a steady state drainage system a drain flow formula coupled with the Dupuit-Forcheimer form of the differential equation of groundwater flow is used. At first, in this paper the most applied drain flow formulas in steady-state conditions are reviewed and compared using as dependent variable the ratio between the maximum water table height and the distance between two lines of parallel drains. These equation are also tested using experimental field data measured in three plot drained by surface pipe drains having different value of drain spacing. Then, applying the dimensional analysis and the self-similarity theory, a new drain spacing formula is theoretically deduced and comp…

Three-dimensional analysis of load transfer micro-mechanisms in fibre/matrix composites

2009

International audience; This study gives a detailed analysis of load distributions around fibre breaks in a composite. In contrast to other studies reported in the literature, the analysis considers different configurations of composite damage from the failure of a few to the failure of many fibres. The model considers three types of matrix behaviours (elastic, elastic–plastic and viscoelastic) with or without debonding at the broken fibre/matrix interface. In this way, the usual limitations of the finite element approach are overcome so as to take into account the number and interactions of broken fibres whilst maintaining an evaluation of the various fields (stresses in particular).

Effects of Boulder Arrangement on Flow Resistance Due to Macro-Scale Bed Roughness

2023

Flow resistance in gravel-bed channels is not only affected by the shape and size of the roughness elements, but also by their arrangement on the channel bed surface (position to flow streamlines, spacing between elements, and their protrusion from the channel bed). Many investigations proved that open channel flow resistance can be obtained by integrating the power velocity profile. For a macro-scale roughness condition, this study aims to investigate the effect of different boulder arrangements on flow resistance. First, for each arrangement, the equation relating Γ function of the power velocity profile, the Froude number, and the channel slope was calibrated using available measur…

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…

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…