Water flow measurement in large bore pipes: An experimental comparison between two different types of insertion flowmeters

2003 ◽  
Vol 42 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Furio Cascetta ◽  
Adolfo Palombo ◽  
Gianfranco Scalabrini
Author(s):  
Anatoly Kusher

The reliability of water flow measurement in irrigational canals depends on the measurement method and design features of the flow-measuring structure and the upstream flow velocity profile. The flow velocity profile is a function of the channel geometry and wall roughness. The article presents the study results of the influence of the upstream flow velocity profile on the discharge measurement accuracy. For this, the physical and numerical modeling of two structures was carried out: a critical depth flume and a hydrometric overfall in a rectangular channel. According to the data of numerical simulation of the critical depth flume with a uniform and parabolic (1/7) velocity profile in the upstream channel, the values of water discharge differ very little from the experimental values in the laboratory model with a similar geometry (δ < 2 %). In contrast to the critical depth flume, a change in the velocity profile only due to an increase in the height of the bottom roughness by 3 mm causes a decrease of the overfall discharge coefficient by 4…5 %. According to the results of the numerical and physical modeling, it was found that an increase of backwater by hydrometric structure reduces the influence of the upstream flow velocity profile and increases the reliability of water flow measurements.


Author(s):  
Alejandro Ibarz ◽  
Gerald Bauer ◽  
Roberto Casas ◽  
Alvaro Marco ◽  
Paul Lukowicz

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1822
Author(s):  
Tingjie Huang ◽  
Yan Lu ◽  
Huaixiang Liu

As a typical waterway modification, the spur dike narrows the water cross section, which increases the flow velocity and flushes the riverbed. Meanwhile, it also protects ecological diversity and improves river habitat. Different types of spur dikes could greatly impact the interaction between flow structure and local geomorphology, which in turn affects the evolution of river aquatic habitats. Four different types of spur dikes—including rock-fill, permeable, w-shaped rock-fill, and w-shaped permeable—were evaluated using flume experiments for spur dike hydrodynamics and fish aggregation effects. Based on Shannon’s entropy, an index for calculating water flow diversity is proposed. Additionally, the impact of the different spur dikes on water flow diversity and the relationship between water flow diversity and fish aggregation effects were studied. The water flow diversity index around the spur dike varied from 1.13 to 2.96. The average aggregation rate of test fish around the spur dike was 5% to 28%, and the attraction effect increased with increasing water flow diversity. Furthermore, we plotted the relationship between water flow diversity index and average fish aggregation rate. A fish hydroacoustic study conducted on the Laohutan fish-bone dike in the Dongliu reach of downstream Yangtze River showed that the fish aggregation effect of the permeable spur dike was greater than the rock-fill spur dike. These research results could provide theoretical support for habitat heterogeneity research and ecologically optimal design of spur dikes.


2020 ◽  
Author(s):  
María Cabrera Fernández

&lt;p&gt;In recent years, there has been an increasing number of studies about freshwater micro-litter&amp;#160; and how it ends up in the ocean.&amp;#160;Nevertheless, macro-litter studies are not common in freshwater landscapes and yet less frequent among rivers. Almost always, research is focused on estuaries rather than rivers.&lt;/p&gt;&lt;p&gt;The Asociaci&amp;#243;n Paisaje Limpio has been developed, for some years, several studies as an affordable methodology to measure macro-litter in rivers throughout its.&lt;/p&gt;&lt;p&gt;This way, our methodology is a combination between research and action. We don&amp;#8217;t just tackle the macro-litter data field, but also identify specific litter problems along the river. We act through campaigns, agreement for companies and public administrations, etc.&lt;/p&gt;&lt;p&gt;A need have been observed to combined different types of methodology to monitoring different types of rivers in order to be able to draw a conclusion:&lt;/p&gt;&lt;ul&gt;&lt;li&gt;&lt;strong&gt;Visual counting&lt;/strong&gt;: counting floating macro-litter on &lt;strong&gt;surface&amp;#160;&lt;/strong&gt;using RIMMEL app.&lt;/li&gt; &lt;li&gt;By the &lt;strong&gt;riverbank,&lt;/strong&gt;through a &lt;strong&gt;Citizen Science&lt;/strong&gt; tool create by Asociaci&amp;#243;n Paisaje Limpio and Asociaci&amp;#243;n Vertidos Cero, called &lt;strong&gt;eLitter&lt;/strong&gt;. Elitter&amp;#160;is harmonized with other marine-litter methodologies (Marine litter watch, MARNOBA in Spain) and its litter classification is based on OSPAR protocol.&lt;/li&gt; &lt;li&gt;If the &lt;strong&gt;riverbed&amp;#160;&lt;/strong&gt;is accessible eLitter is also used, but when is not accessible a dredge &quot;Van Veen&quot; have been used instead. This method has been applied in other marine-litter projects on seabed.&lt;/li&gt; &lt;li&gt;&lt;strong&gt;Floating booms&lt;/strong&gt;: it lets us know plastics rate in captured floating litter, and the water flow extrapolation.&lt;/li&gt; &lt;li&gt;&lt;strong&gt;Nets from a kayak&lt;/strong&gt;: to study the plastic concentration&amp;#160; in &lt;strong&gt;the water column&amp;#160;&lt;/strong&gt;and the water flow extrapolation.&lt;/li&gt; &lt;li&gt;&lt;strong&gt;Water quality general analysis:&lt;/strong&gt;this analysis is useful to support the hypothesis about litter&amp;#8217;s source in a river, mainly where the source is the sewage as happens with wet wipes, ear sticks...&lt;/li&gt; &lt;/ul&gt;&lt;p&gt;-&lt;strong&gt;Case study&lt;/strong&gt;: river Lagares, a spanish river in Pontevedra, Galicia.&amp;#160;The river Lagares flows into the Atlantic, in a Special Protection Area (SPA), a designation under the European Union Directive on the Conservation of Wild Birds.&lt;/p&gt;&lt;p&gt;The Asociaci&amp;#243;n Paisaje Limpio is working on this river since 2018. We have applied the different methodologies explained before, in the river Lagares.&lt;/p&gt;


2019 ◽  
Vol 16 (1) ◽  
pp. 95-106
Author(s):  
Munadi ◽  
Imam Solekhudin ◽  
Sumardi ◽  
Atok Zulijanto

2014 ◽  
Vol 926-930 ◽  
pp. 1412-1416
Author(s):  
Shi Ming Wang ◽  
Zhen Wang ◽  
Qing Yi He ◽  
Jie Zhang ◽  
Yu Qing Zhang

SLC9-2-type direct reading; current meter is a lightweight, reliable, affordable, low consumption of the new flow measurement instruments, available for measuring the different depth of water flow speed and direction in the ocean, bays, rivers, lakes, reservoirs, estuaries . By improving its structure, using the simulation analysis of ANSYS software, it analyzes the new structure on the impact of lowing start. Simulation results for the actual SLC9-2-type direct reading current meter provide guidance for new design.


2017 ◽  
Vol 117 ◽  
pp. 306-313 ◽  
Author(s):  
Meda Venkata Nitesh ◽  
S. Arjun ◽  
Shaik Afzal Ahammed ◽  
P. Ramesh ◽  
N.C. Lenin

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