A simple flow-metering device for use in flood irrigation experiments

1964 ◽  
Vol 4 (12) ◽  
pp. 49
Author(s):  
RI Baxter
Keyword(s):  
Head Loss ◽  
Surface Irrigation ◽  
Flow Conditions ◽  
Flood Irrigation ◽  
Simple Version ◽  
Flow Metering ◽  
Irrigation Channels ◽  
Adequate Accuracy ◽  
Simple Flow

A flow-metering device has been developed for the measurement of rate of flow of water for flows up to one cubic foot per second from surface irrigation channels on to flood-irrigated land with a head difference less than six inches. Approach flow conditions do not affect the relation between rate of flow and head loss across the meter within the degree of accuracy required. A simple version of this meter is cheap to construct and gives adequate accuracy.

scholarly journals Local head loss caused in connections used in micro-irrigation systems

2019 ◽  
Vol 23 (7) ◽  
pp. 492-498 ◽  
Author(s):  
Wagner W. Á. Bombardelli ◽  
Antonio P. de Camargo ◽  
José A. Frizzone ◽  
Rogério Lavanholi ◽  
Hermes S. da Rocha
Keyword(s):  
Flow Rate ◽  
Head Loss ◽  
International Standards ◽  
Flow Conditions ◽  
Irrigation Systems ◽  
Head Losses ◽  
Satisfactory Performance ◽  
Head Loss Coefficient ◽  
Micro Irrigation ◽  
The One

ABSTRACT Information about local head loss caused by connections employed in micro-irrigation systems is hard to be found in literature. The objective of this research was to experimentally determine the local head losses in connections commonly used in micro-irrigation and propose mathematical models using the theorem of Buckingham. The methodology of tests was based on international standards. The tests were carried out under controlled inlet pressure, at 150 kPa, and five to ten units of each connection model were tested. The curves relating flow and head losses were drawn based on 15 flow conditions, obtained under increase and decrease of flow rate. For each condition, 30 points were collected resulting in a sample size of 900 points in each test. For each connection model evaluated, the following information was obtained: curves of local head loss as a function of flow rate and of local head loss coefficient (KL). The obtained values of KL ranged from 2.72 to 24.16, which become constant for Reynolds number higher than 10,000. The sensitivity of the coefficient related to a ratio of the internal sections in the connections was also verified. The flow exponents presented values close to the one applied by the Darcy-Weisbach equation (m = 2). The models developed for the connections presented a satisfactory performance.

scholarly journals Physical Simulation for the Flow in Straight and Rectangular Loop Manifolds

2021 ◽  
Vol 27 (3) ◽  
pp. 15-32
Author(s):  
Abdullah A. Rihan ◽  
Thamer A. Mohamed ◽  
Dr. Wissam H. Alawee
Keyword(s):  
Physical Simulation ◽  
Flow Distribution ◽  
Head Loss ◽  
Flow Conditions ◽  
Factors Affecting ◽  
Uniformity Coefficient ◽  
Head Losses ◽  
Supply Tank ◽  
Total Head ◽  
Constant Head

The flow in a manifolds considered as an advanced problem in hydraulic engineering applications. The objectives of this study are to determine; the uniformity qn/q1 (ratio of the discharge at last outlet, qn to the discharge at first outlet, q1) and total head losses of the flow along straight and rectangular loop manifolds with different flow conditions. The straight pipes were with 18 m and 19 m long and with of 25.4 mm (1.0 in) in diameter each. While, the rectangular close loop configuration was with length of 19 m and with diameter of 25.4 mm (1.0 in) also. Constant head in the supply tank was used and the head is 2.10 m. It is found that outlets spacing and manifold configuration are the main factors affecting the uniformity of flow distribution and friction head losses along manifolds. For large value of outlets spacing, the uniformity coefficient (qn/q1) was found with greatest value of 0.96. Thus, the flow distribution improves with bigger spacing between outlets along manifold. For same manifold length, diameter, inlet head and spacing between outlets (S/L=0.079), the uniformity coefficient was found 0.881 or 88.1% for straight manifold and 0.926 for rectangular loop manifold. From the experimental data, a better uniformity is obtained from the rectangular loop manifold, this is because the friction head loss in rectangular loop manifold was lower than that in straight manifold. The lowest of total head losses was found with greatest outlet spacing along manifold, while the highest of total head losses was found with smallest outlets spacing along manifold. And, the lowest of total head loss was found with the rectangular manifold, while the highest of total head loss was found with the straight manifold.

scholarly journals Flow environment and matrix structure interact to determine spatial competition inPseudomonas aeruginosabiofilms

2016 ◽  
Author(s):  
Carey D. Nadell ◽  
Deirdre Ricaurte ◽  
Jing Yan ◽  
Knut Drescher ◽  
Bonnie L. Bassler
Keyword(s):  
Spatial Competition ◽  
Flow Speed ◽  
Hydrodynamic Flow ◽  
Natural Environments ◽  
Wild Type ◽  
Flow Conditions ◽  
Matrix Organization ◽  
Matrix Production ◽  
Spatial Architecture ◽  
Simple Flow

AbstractBacteria often live in biofilms, which are microbial communities surrounded by a secreted extracellular matrix. Here, we demonstrate that hydrodynamic flow and matrix organization interact to shape competitive dynamics inPseudomonas aeruginosabiofilms. Irrespective of initial frequency, in competition with matrix mutants, wild type cells always increase in relative abundance in straight-tunnel microfluidic devices under simple flow regimes. By contrast, in microenvironments with complex, irregular flow profiles - which are common in natural environments - wild type matrix-producing and isogenic non-producing strains can coexist. This result stems from local obstruction of flow by wild-type matrix producers, which generates regions of near-zero flow speed that allow matrix mutants to locally accumulate. Our findings connect the evolutionary stability of matrix production with the hydrodynamics and spatial structure of the surrounding environment, providing a potential explanation for the variation in biofilm matrix secretion observed among bacteria in natural environments.Impact StatementThe feedback between hydrodynamic flow conditions and biofilm spatial architecture drives competition inP. aeruginosabiofilms, and can explain the variation in biofilm production observed among bacteria in natural environments.

A Unifying Method for Sizing Throttling Valves Under Laminar or Transitional Flow Conditions

1993 ◽  
Vol 115 (1) ◽  
pp. 166-169
Author(s):  
H. D. Baumann
Keyword(s):  
Experimental Data ◽  
Reynolds Number ◽  
Laminar Flow ◽  
Prediction Method ◽  
Head Loss ◽  
Transitional Flow ◽  
Velocity Head ◽  
Reasonable Accuracy ◽  
Flow Conditions ◽  
Head Loss Coefficient

The mass flow passing through a given valve will decrease in Reynolds number ranges below approximately 10,000 due to the transition from fully developed turbulent to laminar flow. The objective of this study is to provide a uniform prediction method to establish, with reasonable accuracy, the ratio between the turbulent and transitional or laminar flow rate passing through a given valve, taking into account the valve’s hydraulic diameter and the initial turbulent velocity head loss coefficient. Experimental data from prior research tends to support a proposed “unified sizing method” that is applicable for all single-stage valves regardless of size or type.

Velocities Induced by The Vortex Wake of a Propeller in a Duct

1963 ◽  
Vol 67 (635) ◽  
pp. 731-733
Author(s):  
Robert Hickling
Keyword(s):  
Radial Flow ◽  
Vortex Sheet ◽  
Flow Conditions ◽  
Propeller Blade ◽  
Vortex System ◽  
Vortex Sheets ◽  
Ducted Propeller ◽  
Lifting Line ◽  
Far Wake ◽  
Simple Flow

If it is assumed that the effect of radial flow can be neglected, then the vortices which are shed from the trailing edge of a propeller blade can be said to lie approximately on helical lines. These vortices form a vortex sheet which for practical purposes is assumed to extend unaltered downstream to infinity. If the propeller blade is approximated by a lifting-line of bound vorticity, then the velocities at the blade induced by the trailing vortex system can be derived from the simple flow conditions in the hypothetical far wake where the vortex sheets extend equally to infinity in both directions. Results are already well-known for the case where the vortex sheets exist in free space. It is the purpose here to examine the effect of adjacent boundaries, such as the hub and the duct wall of a ducted propeller. The results also relate to a test propeller in a tunnel.

scholarly journals ESPACIALIZAÇÃO DE CANAIS DE IRRIGAÇÃO POR SULCO COM AUXILIO DE SOFTWARES

Irriga ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 53-59
Author(s):  
RENNAN SALVIANO TERTO ◽  
THALES RAFAEL GUIMARÃES QUEIROZ ◽  
MÁRCIO REGYS RABELO DE OLIVEIRA ◽  
PEDRO VICTOR VERAS PAIVA ◽  
RAIMUNDO NONATO TÁVORA COSTA
Keyword(s):  
Three Dimensional ◽  
Soil Surface ◽  
Surface Irrigation ◽  
Soil Movement ◽  
Experimental Area ◽  
Topographic Survey ◽  
Irrigation Channels ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
E Mail

ESPACIALIZAÇÃO DE CANAIS DE IRRIGAÇÃO POR SULCO COM AUXILIO DE SOFTWARES     RENNAN SALVIANO TERTO1; THALES RAFAEL GUIMARÃES QUEIROZ2; MÁRCIO REGYS RABELO DE OLIVEIRA3; PEDRO VICTOR VERAS PAIVA4 E RAIMUNDO NONATO TÁVORA COSTA5   1 Departamento de Engenharia Agrícola, Universidade Federal do Ceará, Centro de Ciências Agrárias – CCA/UFC-Bloco 804, Avenida Mister Hull, s/n-CEP: 60.455-760, Fortaleza, CE, Brasil, e-mail: [email protected]; 2 Departamento de Engenharia Agrícola, Universidade Federal do Ceará, Centro de Ciências Agrárias – CCA/UFC-Bloco 804, Avenida Mister Hull, s/n-CEP: 60.455-760, Fortaleza, CE, Brasil, e-mail:  [email protected]; 3 Departamento de Engenharia Agrícola, Universidade Federal do Ceará, Centro de Ciências Agrárias – CCA/UFC-Bloco 804, Avenida Mister Hull, s/n-CEP: 60.455-760, Fortaleza, CE, Brasil, e-mail:  [email protected]; 4 Departamento de Engenharia Agrícola, Universidade Federal do Ceará, Centro de Ciências Agrárias – CCA/UFC-Bloco 804, Avenida Mister Hull, s/n-CEP: 60.455-760, Fortaleza, CE, Brasil, e-mail:  [email protected]; 5 Departamento de Engenharia Agrícola, Universidade Federal do Ceará, Centro de Ciências Agrárias – CCA/UFC-Bloco 804, Avenida Mister Hull, s/n-CEP: 60.455-760, Fortaleza, CE, Brasil, e-mail:  [email protected].     1 RESUMO   A irrigação por superfície é caracterizada pela aplicação de água diretamente sobre a superfície do solo da área a ser irrigada. O SURFER® é um programa utilizado para a confecção de mapas, já o software Plano Fácil, tem aplicações em projetos de irrigação e drenagem que necessitam trabalhar com a sistematização de áreas. Diante do exposto, o trabalho teve como objetivo identificar a melhor disposição dos canais de irrigação que propiciem menor movimentação de solo através do uso dos softwares SURFER® e Plano Fácil. O estudo foi realizado na área experimental do Laboratório de Hidráulica e Irrigação da Universidade Federal do Ceará, campus do Pici, Fortaleza-CE. Utilizou-se um terreno com formato quadriculado subdividido em quadrículas com lados de 20 m x 30 m. Utilizou-se a área de maior dimensão a qual foi estaqueada para obtenção das cotas do terreno por nivelamento geométrico contra o nivelamento, para encerrar, a sistematização de terrenos usou-se os softwares Plano Fácil e Surfer versão 07, para obter o menor movimento de solo no processo corte e aterro. A sistematização da área através do uso dos softwares permitiu a espacialização nos modelos tridimensionais dos canais de irrigação com a menor movimentação de solo.   Palavras-chave: levantamento topográfico, sistematização, superfície       TERTO, R. S.; QUEIROZ, T. R. G.; OLIVEIRA, M. R. R. DE; PAIVA, P. V. V.; COSTA, R. N. T. IRRIGATION CHANNELS ESPACIALIZATION BY FURROW WITH SOFTWARE ASSISTANCE     2 ABSTRACT   Surface irrigation is characterized by the application of water directly on the soil surface of the area to be irrigated. SURFER® is a program used for making maps, and the software Plano Facil, has applications in irrigation and drainage projects that need to work with the systematization of areas. Based on the above considerations, the study aimed to identify the best arrangement of irrigation channels that allow less soil movement using SURFER® and Plano Facil softwares. The study was conducted in the experimental area of ​​the Laboratory of Hydraulics and Irrigation of the Federal University of Ceara, Campus of Pici, Fortaleza-CE. It was used a square-shaped terrain subdivided into squares with sides of 20 m x 30 m, which was staked to obtain the terrain dimensions by geometric leveling. The Plano Facil and Surfer version 11 softwares were used to process the data and respective values ​​of cuts and backfills. The systematization of the area through the use of the softwares allowed the spatialization in the three-dimensional models of irrigation channels with the lowest soil movement.   Keywords: surface, systematization, topographic survey.

Dynamic Deformation Analysis of a Red Blood Cell in Steady and Unsteady Shear Flows

2008 ◽  
Author(s):  
Sadao Bessho ◽  
Masanori Nakamura ◽  
Kenichirou Koshiyama ◽  
Shigeo Wada
Keyword(s):  
Velocity Field ◽  
Blood Cells ◽  
Predictive Accuracy ◽  
Dynamic Deformation ◽  
Artificial Organs ◽  
Deformation Analysis ◽  
Flow Conditions ◽  
Flow Velocity Field ◽  
Dynamical Deformation ◽  
Simple Flow

Quantitative evaluation of hemolysis, the breaking open of red blood cells (RBCs), is essential in designing artificial organs. Recently, numerical methods to quantify hemolysis from a measured or calculated macroscopic flow velocity field have been proposed [1]. Nevertheless, their predictive accuracy has not reached a satisfactory level required in practice. This would be because the conventional methods are mostly established based on the hemolysis tests under simple flow conditions and have not well considered deformation of RBCs. For further amelioration of the predictive accuracy, it would be necessary to take into account motion and dynamical deformation of individual RBCs in a flow field.

Thrombus formation on artificial surfaces: Correlative microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 840-841
Author(s):  
Quintin J. Lai ◽  
Stuart L. Cooper ◽  
Ralph M. Albrecht
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Low Voltage ◽  
Thrombus Formation ◽  
Blood Platelets ◽  
Polymer Surfaces ◽  
Flow Conditions ◽  
Transmission Electron ◽  
Adhesion Of Platelets ◽  
Microscopic Techniques

Thrombus formation and embolization are significant problems for blood-contacting biomedical devices. Two major components of thrombi are blood platelets and the plasma protein, fibrinogen. Previous studies have examined interactions of platelets with polymer surfaces, fibrinogen with platelets, and platelets in suspension with spreading platelets attached to surfaces. Correlative microscopic techniques permit light microscopic observations of labeled living platelets, under static or flow conditions, followed by the observation of identical platelets by electron microscopy. Videoenhanced, differential interference contrast (DIC) light microscopy permits high-resolution, real-time imaging of live platelets and their interactions with surfaces. Interference reflection microscopy (IRM) provides information on the focal adhesion of platelets on surfaces. High voltage, transmission electron microscopy (HVEM) allows observation of platelet cytoskeletal structure of whole mount preparations. Low-voltage, high resolution, scanning electron microscopy allows observation of fine surface detail of platelets. Colloidal gold-labeled fibrinogen, used to identify the Gp Ilb/IIIa membrane receptor for fibrinogen, can be detected in all the above microscopies.

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