Search results for "Maximum flow problem"

showing 3 items of 3 documents

Application of entropic approach to estimate the mean flow velocity and Manning roughness coefficient in a high-curvature flume

2016

The entropy-based approach allows the estimation of the mean flow velocity in open channel flow by using the maximum flow velocity. The linear relationship between the mean velocity, umax, and the mean flow velocity, um, through the dimensionless parameter Φ(M), has been verified both in natural rivers and in laboratory channels. Recently, the authors of this study investigated the reliability of the entropy-based formula in a straight channel and under different bed and side-walls' roughness conditions. The present study aims to further validate the entropy-based approach and to explore the effectiveness of entropy-based formula in high curvature channels. Results show that as the effect o…

010504 meteorology & atmospheric sciencesChézy formulaAdvection0208 environmental biotechnologyMaximum flow problemMathematical analysis02 engineering and technologyCurvature01 natural sciencesSettore ICAR/01 - Idraulica020801 environmental engineeringOpen-channel flowRivers monitoring simulation discharge entropy experimentsFlumeStatisticsEntropy (information theory)0105 earth and related environmental sciencesWater Science and TechnologyMathematicsDimensionless quantityHydrology Research
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Analysing longitudinal turbulence intensity in vegetated channels

2007

Vegetation altering hydrodynamic conditions of an open channel flow controls the exchanges of sediment, nutrients and contaminants. In this paper the turbulence structure of open-channel flow over a flexible grass vegetation is investigated. Velocity measurements were carried out, in a rectangular flume, using a 2D-ADV (Acoustic Doppler Velocimeter) for different values of stem concentration, water discharge, and bed slope. The experimental results showed that: 1) the maximum value of the longitudinal turbulence intensity occurs at a water depth close to the bent vegetation height; 2) the turbulence intensity damps for increasing values of the stem concentration; 3) above the vegetation hei…

TurbulenceMechanical EngineeringMaximum flow problemFlow (psychology)lcsh:SBioengineeringAtmospheric scienceslcsh:S1-972Industrial and Manufacturing EngineeringOpen-channel flowopen-channel turbulence vegetationlcsh:AgriculturePhysics::Fluid DynamicsFlumeVegetated channels Flexible vegetation Acoustic Doppler Velocimeter Turbulence intensity Relative turbulence intensity.Turbulence kinetic energymedicineEnvironmental scienceAcoustic Doppler velocimetrylcsh:Agriculture (General)medicine.symptomVegetation (pathology)
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Normalwerterstellung von Blutströmungsgeschwindigkeiten an der Arteria mesenterica superior bei Früh- und Reifgeborenen mit der Duplexsonographie

1994

In a prospective study blood flow velocity measurements were performed in 110 "healthy" newborn with duplex Doppler sonography in the superior mesenteric artery to obtain standard values. In 49 of these neonates 15, 30, and 45 minutes following feeding examinations were performed. Peak systolic flow velocity, end systolic flow velocity, time average flow velocity and time average maximum flow velocity were determined, the resistance and Pourcelot index as well as the volume blood flow were calculated. The children's gestational age was 27-42 weeks, the postnatal age was 2-68 days and the body weight was 920-4190 g. All measured blood flow velocities showed a synchronous relation to feeding …

medicine.medical_specialtybusiness.industryMaximum flow problemGestational ageNormal valuesBlood flowSurgeryPostnatal ageFlow velocityInternal medicinemedicine.arterymedicineCardiologyRadiology Nuclear Medicine and imagingSuperior mesenteric arteryProspective cohort studybusinessRöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren
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