نتایج جستجو برای: hydraulic coefficient

تعداد نتایج: 196741  

2000
R. Burrows Q. Qiu

sures experienced by a pipeline can be either beneficial or detrimental from an operational performance perspective, depending on the amount, the two phase regime of the mixture (whether homogeneous or slug) and the nature and cause of the transient. It is generally held that when free (undissolved) air, or gas, is present in a hydraulic system, it can greatly reduce the surge pressure levels b...

Journal: :تحقیقات آب و خاک ایران 0
سارا باقری منوچهر حیدرپور

circular- crested weirs are employed for flow measurement among their other wide applications in hydraulic engineering. they can also be used to control water level in farm ponds and reservoirs. advantages of the circular crested weirs as compared to other weirs include the stable overflow pattern, the simplicity of design and their associated lower costs. in this study, the curvilinear flow pa...

Using experimental models along with conducting numerical analysis have been widely used in performance recognition and optimization of hydraulic equipments. Numerical modeling has lower cost rather than experimental one; however practical tests are commonly used because of the hydraulic structure importance especially in dams. Meanwhile numerical methods could be used for future designs throug...

2018
David Valentin Alexandre Presas Matias Bossio Mònica Egusquiza Eduard Egusquiza Carme Valero

Nowadays, hydropower plays an essential role in the energy market. Due to their fast response and regulation capacity, hydraulic turbines operate at off-design conditions with a high number of starts and stops. In this situation, dynamic loads and stresses over the structure are high, registering some failures over time, especially in the runner. Therefore, it is important to know the dynamic r...

ژورنال: علوم آب و خاک 2014
حسینی, یاسین , حیدرپور, منوچهر , رضویان, سید حسین ,

The combined system of gate and weir is used for flow measurement in open channels. But in case the passing water has floating material and sediment it damages their performance and hence error of measurement will increase. In order to solve this problem, weir and gate can be combined and a concentrated hydraulic system known as weir-gate can be developed, thus allowing sediments transportation...

ژورنال: علوم آب و خاک 2019

Labyrinth weirs are the economic structures to increase the weir output efficiency in limited widths, which can be seen in the plane f trapezoidal and triangular forms. These weirs with a hydraulic load and fixed width pass the more discharge in comparison to other type of weirs. In this study, labyrinth weirs trapezoidal in plane form were investigated. The experiments were performed on 27 lab...

Journal: :journal of applied research in water and wastewater 2014
abbas parsaie amir hamzeh haghiabi

allocation and removing of excess water from the irrigation and drainage network is one of the most important activities in the management of these networks. side weir is one of the most common structures for this purpose. study on the flow hydraulic characteristics of this structure included two parts, defining the water surface profiles and estimating the discharge coefficient. to estimate th...

1997
V. I. NIKORA D. G. GORING B. J. F. BIGGS

A set of experiments was carried out to determine what effects periphyton communities could have on near-bed hydraulic fields. We analysed velocity distribution, skewness and kurtosis coefficients, Reynolds stresses, relative turbulence intensity, coefficient of eddy diffusivity, velocity spectra, and turbulence scales at two flows with, and without, diatom-dominated periphyton on the bed. We f...

2004
Orazio Giustolisi

Genetic Programming has been used to determine Chèzy resistance coefficient for full circular corrugated channels. Three corrugated plastic pipes have been experimentally studied in order to generate data. The tests aim at measuring hydraulic parameters of the open-channel flow for some slopes, from 3.49–17.37% (2–10°), in order to discover the dependence of the channel resistance coefficient w...

2016
Y. H. Spitz J. M. Klinck

Dynamical assimilation of surface elevation from tide gauges is investigated to estimate the bottom drag coefficient and surface stress as a first step in improving modeled tidal and wind-driven circulation in the Chesapeake Bay. A two-dimensional shallow water model and an adjoint variational method with a limited memory quasi-Newton optimization algorithm are used to achieve this goal. Assimi...

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