Search results for "meander"
showing 10 items of 38 documents
Effects of submerged vegetation on flow and turbulence characteristics at the apex section of a meandering flume
2020
Understanding flow characteristics and turbulent structure in the presence of vegetation is important with respect to environmental processes as sediment transport and mixing of transported quantities. In the present paper attention is focused on the kinematic and turbulent processes in presence of flexible submerged vegetation. In particular, the effect of vegetation on the flux of mass distribution and the process of transport is investigated. The analysis is performed with the aid of detailed experimental data collected in a laboratory channel both in the absence and in presence of flexible and submerged vegetation. Results essentially confirms that mass exchanges in the presence of vege…
Effects of submerged vegetation on flow and turbulence characteristics at the apex bend of a meandering flume
2020
Understanding flow characteristics and turbulent structure in the presence of vegetation is important with respect to environmental processes as sediment transport and mixing of transported quantities. In the present paper attention is focused on the kinematic and turbulent processes in presence of flexible submerged vegetation. In particular, the effect of vegetation on the flux of mass distribution and the process of transport is investigated. The analysis is performed with the aid of detailed experimental data collected in a laboratory channel both in the absence and in presence of flexible and submerged vegetation. Results essentially confirms that mass exchanges in the presence of vege…
Cross-sectional flow and bed shear stress: application of the depth-averaged momentum equation in a meandering laboratory flume
2014
Studio dell’interazione corrente-vegetazione in un alveo meandriforme di elevata ampiezza in presenza di vegetazione sommersa matura e non ed al vari…
Bank Erosion and Secondary Circulation in a Meandering Laboratory Flume
2014
Abstract This paper reports peculiar results of experimental investigation on the secondary circulation motion of flow along a meander wave. Experiments were conducted in a large amplitude meandering laboratory channel for two values of the width-to-depth ratio. Here attention is focalized on how secondary motion affects the bank shear stress distribution, influencing the stability of the outer bank. The analysis essentially highlights that, especially for small width-to-depth ratio, as the channel curvature increases, besides the classical central-region secondary circulation cell a counter-rotating circulation cell forms in the outer-bank region. Such counter-rotating circulation cell all…
Experiments on Longitudinal and Transverse Bedload Transport in Sine-Generated Meandering Channels
2021
Bedload grains in consecutive meandering bends either move longitudinally or across the channel centerline. This study traces and quantifies the grains’ movement in two laboratorial sine-generated channels, i.e., one with deflection angle θ0 = 30° and the other 110°. The grains originally paved along the channels are uniform in size with D = 1 mm and are dyed in various colors, according to their initial location. The experiments recorded the changes in the flow patterns, bed deformation, and the gain-loss distribution of the colored grains in the pool-bar complexes. We observed the formation of two types of erosion zones during the process of the bed deformation, i.e., Zone 1 in the foresi…
Investigation on Metal–Oxide Graphene Field-Effect Transistors With Clamped Geometries
2019
In this work, we report on the design, fabrication and characterization of Metal-Oxide Graphene Field-effect Transistors (MOGFETs) exploiting novel clamped gate geometries aimed at enhancing the device transconductance. The fabricated devices employ clamped metal contacts also for source and drain, as well as an optimized graphene meandered pattern for source contacting, in order to reduce parasitic resistance. Our experimental results demonstrate that MOGFETs with the proposed structure show improved high frequency performance, in terms of maximum available gain and transition frequency values, as a consequence of the higher equivalent transconductance obtained.
Dip Phenomenon in High-Curved Turbulent Flows and Application of Entropy Theory
2018
The estimation of velocity profile in turbulent open channels is a difficult task due to the significant effects of the secondary flow. The present paper investigates the mechanism of the velocity-dip phenomenon, whereby the location of the maximum velocity appears to be below the free surface. Previous studies conducted in straight channels relate the mechanism of the velocity-dip phenomenon to secondary flow induced by anisotropy of turbulence. This work focuses on high-curved channels where the secondary motion, which is also induced by the channel’s curvature, evolves along the bend. The width-to-depth ratio, B/h, is one of the most important parameters that are affecting the secondary …