scholarly journals Calibration of Stainless Steel-edged V-Notch Weir Stop Logs for Water Level Control Structures

2019 ◽  
Vol 35 (5) ◽  
pp. 745-749
Author(s):  
L. E. Christianson ◽  
R. D. Christianson ◽  
A. E. Lipka ◽  
S. Bailey ◽  
J. Chandrasoma ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Water Level ◽  
Flow Rate ◽  
Subsurface Drainage ◽  
Conservation Practices ◽  
Nutrient Loads ◽  
Level Control ◽  
Control Structures ◽  
Flow Monitoring ◽  
Flow Through

Abstract. Dependable flow rate measurements are necessary to calculate flow volumes and resulting nutrient loads from subsurface drainage systems and associated conservation practices. The objectives of this study were (1) to develop appropriate weir equations for a new stainless steel-edged 45° V-notch weir developed for AgriDrain inline water level control structures and (2) to determine if the equation was independent of flow depth in the structure. Weirs for 15 cm (6 in.) and 25 cm (10 in.) inline water level control structures were placed at three heights in each structure: at the base, 48 cm from the base, or 97 cm from the base, and the height of the nappe above the weir crest was recorded over a range of flow rates. The resulting data were fitted to equations of the form Q = aHb where Q is the flow rate, H is the height of the nappe above the weir crest, and a and b are fitted parameters. There were no significant differences in the fitted parameters across the two structure sizes or across the three weir placements. The fitted equation for these new stainless steel-edged V-notch weirs was Q = 0.011H2.28 with Q in liters per second and H in centimeters, and Q = 1.44H2.28, with Q in gallons per minute and H in inches. These equations can be used for measuring flow through AgriDrain in-line structures, although in-house weir calibration is highly recommended for specific applications, when possible. Keywords: Drainage, Flow monitoring, Subsurface drainage, V-notch weir, Weir calibration.

scholarly journals Assessment of Equivalence of Small and Large Orifice Computational Models

2015 ◽  
Vol 62 (3-4) ◽  
pp. 67-76
Author(s):  
Michał Kubrak
Keyword(s):  
Theoretical Analysis ◽  
Water Level ◽  
Water Flow ◽  
Flow Rate ◽  
Computational Models ◽  
Volumetric Flow Rate ◽  
Maximum Value ◽  
Water Head ◽  
Large Orifice ◽  
Flow Through

AbstractThe aim of this paper was to analyze theoretical aspects of calculating steady water flow through unsubmerged circular orifices. Theoretical analysis shows that the values of discharge obtained by using formulas intended for small orifices are greater than those calculated using formulas for large orifices. These differences attain a maximum value when the water level reaches the upper edge of the orifice, and decrease when water head increases. It has been proven that the volumetric flow rate for circular unsubmerged orifices can be calculated by formulas for small orifices when the water level above the center of gravity is at least four times as high as the diameter of the orifice.

scholarly journals Use of bottom slots and submerged vanes for controlling sediment upstream of duckbill weirs

2020 ◽  
Vol 20 (8) ◽  
pp. 3393-3403
Author(s):  
Mahla Tajari ◽  
Amir Ahmad Dehghani ◽  
Mehdi Meftah Halaghi ◽  
Hazi Azamathulla
Keyword(s):  
Image Processing ◽  
Water Level ◽  
Maximum Relative Error ◽  
Level Control ◽  
Control Structures ◽  
Flow Capacity ◽  
Irrigation Networks ◽  
Weir Height ◽  
Submerged Vanes ◽  
3D Software

Abstract Duckbill weir is one of the water level control structures in irrigation networks, which is of interest to many engineers. Sediments transported in irrigation networks that accumulate upstream of duckbill weirs cause problems in operation, and affect the upstream water level. In this paper, submerged vanes and bottom slots are investigated for flushing the sediment downstream of the said weir. The experiments were conducted in a rectangular flume, 12 m long, and 0.6 m wide. The vanes placed in four sections were perpendicular to the sidewall. Flow-3D software was used for simulation of flow and sedimentation patterns. The results showed that submerged vanes create a secondary flow which is very useful for flushing the sediment, especially in the value of (H is head over the sidewall and P is the weir height). Further, the results showed duckbill weir efficiency (which is defined as the ratio of sediment trap to flow capacity of the weir) is as high as 47% (for values of H/P = 0.1–0.5 and total models). Finally, image processing results showed a maximum relative error of 14.4% for the simulation of the sediment pattern with Flow-3D software.

The case of Lake Balaton: how can we exercise precaution?

2005 ◽  
Vol 52 (6) ◽  
pp. 195-203 ◽  
Author(s):  
L. Somlyódy ◽  
M. Honti
Keyword(s):  
Climate Change ◽  
Water Level ◽  
Natural Water ◽  
Arma Model ◽  
Water Transfer ◽  
Main Question ◽  
Lake Balaton ◽  
Nutrient Loads ◽  
Level Control ◽  
Drought Period

Balaton is the largest shallow lake in Central Europe and the most important recreational area in Hungary. Water balance of the lake is positive, while natural water level fluctuation has been significant. In 2000, an extreme drought period started. Until 2003, water level dropped about 70 cm (about 20% of the average depth). Public concern grew and the idea of water transfer from the Rába River was raised. To examine possible impacts a comprehensive study was prepared. The main question was whether water transfer was really needed and what criterion should be applied. For developing the methodology, three pillars were used: the potential climate change, the precautionary principle and the EU Water Framework Directive. The study covered impacts of the planned water transfer on the Rába–Balaton system in terms of changes of the water regime, water demands and quality, nutrient loads and ecosystems. The Thomas–Fiering ARMA model was used for characterizing monthly change of the natural water resources of the lake. A Monte Carlo generator was developed to analyze the occurrence of extreme events, uncertainties, possible climate change impacts and water level control strategies.

scholarly journals Theoretical and Experimental Analysis of Operating Conditions of a Circular Flap Gate for an Automatic Upstream Water Level Control

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2576
Author(s):  
Janusz Kubrak ◽  
Elżbieta Kubrak ◽  
Edmund Kaca ◽  
Adam Kiczko ◽  
Michał Kubrak
Keyword(s):  
Water Level ◽  
Flow Rate ◽  
Water Depth ◽  
Maximum Flow ◽  
Operating Conditions ◽  
Drainage Ditches ◽  
Level Control ◽  
Flow Rates ◽  
Water Head ◽  
Open Position

This article introduces a flow controller for an upstream water head designed for pipe culverts used in drainage ditches or wells. The regulator is applicable to water flow rates in the range of Qmin < Q < Qmax and the water depth H0, exceeding which causes the gate to open. Qmin flow denotes the minimum flow rate that allows water to accumulate upstream of the controller. Above the maximum flow rate Qmax, the gate remains in the open position. In the present study, the position of the regulator’s gate axis was related to the water depth H0 in front of the device. Derived dependencies were verified in hydraulic experiments. The results confirmed the regulator’s usefulness for controlling the water level.

Water Level Control of Small-scale Hydroelectric Power Plant

2002 ◽  
Vol 122 (6) ◽  
pp. 989-994
Author(s):  
Shinichiro Endo ◽  
Masami Konishi ◽  
Hirosuke Imabayashi ◽  
Hayami Sugiyama
Keyword(s):  
Power Plant ◽  
Water Level ◽  
Hydroelectric Power Plant ◽  
Small Scale ◽  
Hydroelectric Power ◽  
Level Control

Pyrolysis of brown algae (Bifurcaria Bifurcata) in a stainless steel tubular reactor: From a review to a case study

2018 ◽  
Vol 14 (1) ◽  
pp. 31-60 ◽  
Author(s):  
M. Y. Guida ◽  
F. E. Laghchioua ◽  
A. Hannioui
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Flow Rate ◽  
Brown Algae ◽  
Tubular Reactor ◽  
Nitrogen Flow ◽  
Nitrogen Flow Rate ◽  
Bifurcaria Bifurcata ◽  
Bio Oil

This article deals with fast pyrolysis of brown algae, such as Bifurcaria Bifurcata at the range of temperature 300–800 °C in a stainless steel tubular reactor. After a literature review on algae and its importance in renewable sector, a case study was done on pyrolysis of brown algae especially, Bifurcaria Bifurcata. The aim was to experimentally investigate how the temperature, the particle size, the nitrogen flow rate (N2) and the heating rate affect bio-oil, bio-char and gaseous products. These parameters were varied in the ranges of 5–50 °C/min, below 0.2–1 mm and 20–200 mL. min–1, respectively. The maximum bio-oil yield of 41.3wt% was obtained at a pyrolysis temperature of 600 °C, particle size between 0.2–0.5 mm, nitrogen flow rate (N2) of 100 mL. min–1 and heating rate of 5 °C/min. Liquid product obtained under the most suitable and optimal condition was characterized by elemental analysis, 1H-NMR, FT-IR and GC-MS. The analysis of bio-oil showed that bio-oil from Bifurcaria Bifurcata could be a potential source of renewable fuel production and value added chemicals.

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