scholarly journals PERDA DE CARGA EM TUBULAÇÕES E CONEXÕES CONDUZINDO ÁGUA RESIDUARIA DA AVICULTURA

Irriga ◽  
2007 ◽  
Vol 12 (2) ◽  
pp. 225-234
Author(s):  
Silvio Cesar Sampaio ◽  
Elisandro Pires Frigo ◽  
Marcio Antonio Vilas Boas ◽  
Manoel M. F. de Queiroz ◽  
Benedito Martins Gomes ◽  
...  
Keyword(s):  
Head Loss ◽  
Wastewater Irrigation ◽  
Average Decrease ◽  
Head Losses ◽  
Liquid Behavior ◽  
Connection Type ◽  
Poultry Wastewater ◽  
System Project

PERDA DE CARGA EM TUBULAÇÕES E CONEXÕES CONDUZINDO ÁGUA RESIDUARIA DA AVICULTURA  Silvio Cesar Sampaio; Elisandro Pires Frigo; Marcio Antonio Vilas Boas; Manoel M. F. De Queiroz; Benedito Martins Gomes; Larissa Schmatz MallmannRecursos Hídricos e Saneamento Ambiental, Universidade Estadual do Oeste do Paraná, Cascavel, PR  1 RESUMO O presente trabalho visou estimar a perda de carga em tubulações comerciais utilizando como fluido circulante água residuária de avicultura (ARA). As tubulações utilizadas foram de aço galvanizado e PVC, com diâmetros variando entre32 a75 mm. Construiu-se bancadas de testes para perdas de carga localizada e distribuída. Registrou-se dados de vazão e pressão para os variados tubos e conexões, utilizando os diferentes materiais. Na avaliação dos dados encontrados, os mesmos foram tabelados e ajustados a modelos potenciais para a perda de carga distribuída e fator “k” para perda de carga localizada. Como parâmetro de comparação e avaliação também foram registrados dados utilizando como fluído circulante água de abastecimento urbano (AAU). A ARA apresentou em média uma diminuição de 42 e 21% no valor do coeficiente “C” de rugosidade da equação de Hazen-Williams, quando comparado com a AAU, para os tubos de PVC e aço galvanizado, respectivamente. Para a perda de carga distribuída, estima-se um aumento que varia de31 a8% com a ARA em relação à AAU, porém essa diferença é sujeita a variação da vazão. Nas conexões soldáveis a perda de carga localizada com a ARA foi maior que na AAU, ao contrário das conexões rosqueáveis. UNITERMOS: perda de carga, irrigação, hidráulica.  SAMPAIO, S. C.; FRIGO, E. P.; VILAS BOAS, M. A.; QUEIROZ, M. M. F. de; GOMES, B. M.; MALLMANN, L. S. HEAD LOSSES IN PIPELINES AND CONNECTIONS CARRYING POULTRY WASTEWATER  2 ABSTRACT An appropriate hydraulics system project requires knowledge on liquid behavior in pressurized piping. This work aimed to  evaluate head losses in pipelines and connections carrying poultry wastewater. Commercial  pipelines made of galvanized iron and PVC and diameters from1”to3”were used. Poultry wastewater presented an average decrease of 42 and 21% inHazen-Williams´s coefficient values, when compared to water in PVC and galvanized ion pipelines, respectively. In general, head loss in all pipelines increased from 31 to 8% with poltry wastewater in relation to water. The connection type affected the results in localized head loss with poultry wastewater. KEYWORDS: wastewater, irrigation, hydraulics

scholarly journals Modelling head loss along emitting pipes using dimensional analysis

2015 ◽  
Vol 35 (3) ◽  
pp. 442-457 ◽  
Author(s):  
Acácio Perboni ◽  
Jose A. Frizzone ◽  
Antonio P. de Camargo ◽  
Marinaldo F. Pinto
Keyword(s):  
Dimensional Analysis ◽  
Excellent Result ◽  
Head Loss ◽  
Maximum Deviation ◽  
Maximum Relative Error ◽  
Data Set ◽  
Head Losses ◽  
Model Based ◽  
Precision And Accuracy ◽  
Relative Errors

Local head losses must be considered in estimating properly the maximum length of drip irrigation laterals. The aim of this work was to develop a model based on dimensional analysis for calculating head loss along laterals accounting for in-line drippers. Several measurements were performed with 12 models of emitters to obtain the experimental data required for developing and assessing the model. Based on the Camargo & Sentelhas coefficient, the model presented an excellent result in terms of precision and accuracy on estimating head loss. The deviation between estimated and observed values of head loss increased according to the head loss and the maximum deviation reached 0.17 m. The maximum relative error was 33.75% and only 15% of the data set presented relative errors higher than 20%. Neglecting local head losses incurred a higher than estimated maximum lateral length of 19.48% for pressure-compensating drippers and 16.48% for non pressure-compensating drippers.

scholarly journals Major and minor head losses in a hydraulic flow circuit: experimental measurements and a Moody’s diagram application

2020 ◽  
Vol 45 (3) ◽  
pp. 47-56
Author(s):  
Aline Amaral Madeira
Keyword(s):  
Friction Factor ◽  
Correlation Coefficients ◽  
Head Loss ◽  
Rapid Expansion ◽  
Experimental Measurements ◽  
Hydraulic Systems ◽  
Local Loss ◽  
Hydraulic Flow ◽  
Head Losses ◽  
Flow Circuit

Domestic and industrial hydraulic drainage networks have gradually become more complicated because of the cities’ rapid expansion. In surcharged hydraulic systems, the head losses may become rather significant, and should not be neglected because could result in several problems. This work presents an investigation about major and minor head losses in a hydraulic flow circuit, simulating the water transport in a drainage network at room temperature (298.15 K) under atmospheric pressure (101,325 Pa). The losses produced by the fluid viscous effect through the one used cast-iron rectilinear pipe (RP-11) and the localized losses generated by two flow appurtenances, one fully open ball valve (BV-1) and one module of forty-four 90º elbows (90E-8) were experimentally measured. Experimental data generated head-loss curves and their well fitted to potential regressions, displaying correlation coefficients (R2) of 0.9792, 0.9924, and 0.9820 for BV-1, 90E-8, and RP-11, respectively. Head loss experimental equations and local loss coefficients through BV-1 and 90E-8 were determined successfully. The Moody’s diagram application proved to be a quite appropriate tool for an approximate estimation of Darcy-Weisbach friction factor. A good approximation between friction factor values obtained via experimental measurements and the Moody’s diagram was observed with mean absolute deviate of 0.0136.

Head losses at manholes with a 90° bend

1988 ◽  
Vol 15 (5) ◽  
pp. 851-858 ◽  
Author(s):  
J. Marsalek ◽  
B. J. Greck
Keyword(s):  
Key Words ◽  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Head Loss ◽  
Pipe Diameter ◽  
Head Losses ◽  
Junction Geometry ◽  
Pressure Changes

Head and pressure changes were studied at manholes with a 90° bend. For pressurized flow, such changes depend only on junction geometry. Among junction parameters, the benching was found particularly important. Full benchings reaching to the pipe crown produced the lowest head losses, particularly when combined with an enlarged pipe diameter at the junction. Head changes in open-channel flow were significantly smaller than those in pressurized flow. Key words: head loss, manholes, sewer junctions, sewer design, sewer hydraulics.

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 Estimation of Cavitation Limits From Local Head Loss Coefficient

2008 ◽  
Vol 130 (10) ◽  
Author(s):  
Raúl Sánchez ◽  
Luis Juana ◽  
Francisco V. Laguna ◽  
Leonor Rodríguez-Sinobas
Keyword(s):  
Boundary Conditions ◽  
Distribution Systems ◽  
Water Distribution ◽  
Head Loss ◽  
Cavitation Number ◽  
Distribution Analysis ◽  
Simple Formulation ◽  
Vapor Cavity ◽  
Head Losses ◽  
Minimum Value

Cavitation effects in valves and other sudden transitions in water distribution systems are studied as their better understanding and quantification is needed for design and analysis purposes and for predicting and controlling their operation. Two dimensionless coefficients are used to characterize and verify local effects under cavitating flow conditions: the coefficient of local head losses and the minimum value of the cavitation number. In principle, both coefficients must be determined experimentally, but a semianalytical relationship between them is here proposed so that if one of them is known, its value can be used to estimate the corresponding value of the other one. This relationship is experimentally contrasted by measuring head losses and flow rates. It is also shown that cavitation number values, called cavitation limits, such as the critical cavitation limit, can be related in a simple but practical way with the mentioned minimum cavitation number and with a given pressure fluctuation level. Head losses under conditions of cavitation in sharp-edged orifices and valves are predicted for changes in upstream and downstream boundary conditions. An experimental determination of the coefficient of local head losses and the minimum value of the cavitation number is not dependent on the boundary conditions even if vapor cavity extends far enough to reach a downstream pressure tap. Also, the effects of cavitation and displacement of moving parts of valves on head losses can be split. A relatively simple formulation for local head losses including cavitation influence is presented. It can be incorporated to water distribution analysis models to improve their results when cavitation occurs. Likewise, it can also be used to elaborate information about validity limits of head losses in valves and other sudden transitions and to interpret the results of head loss tests.

Flow establishment in helical corrugated pipe

1988 ◽  
Vol 15 (5) ◽  
pp. 912-915 ◽  
Author(s):  
Cliff D. Smit
Keyword(s):  
Friction Factor ◽  
Helix Angle ◽  
Head Loss ◽  
Pipe Length ◽  
Head Losses ◽  
A Value ◽  
Variable Friction ◽  
Smooth Pipe ◽  
Loss Term ◽  
Hydraulics Laboratory

Corrugated steel pipe suppliers have recently switched from annular rivetted corrugated pipe to helical lock seam corrugated pipe. This was done as a manufacturing expedient, but there has been an unexpected benefit in terms of reduced hydraulic resistance. Studies on full scale pipes have shown that the friction factor for full flow is lowered substantially as the helix angle of the corrugations is reduced. In fact at a helix angle of 52.5 ° the pipe resistance was found to be almost as low as for smooth pipe. However, these tests were concerned exclusively with determining rates of head loss for fully established flow. Drainage culverts for highways, grid roads, and farm crossings are usually relatively short structures. In some cases the length to diameter ratio may be as low as 10, and in most cases would not exceed 50. This immediately introduces the question of the length of culvert required to develop fully established helical flow, because before the flow becomes established the rate of head loss will be greater. In effect the friction factor will be highest at the culvert inlet and decrease along the length of the culvert, becoming a minimum after the flow is fully established. In theory the accumulated loss could be calculated by using a variable friction factor over the establishment length. This would be cumbersome and impractical. It would be simpler to calculate the pipe friction on the assumption that it is constant, at the minimum value, for the whole length of the pipe and then add a "development head loss" term to account for the extra loss. Experiments to determine the development head loss were conducted at the Hydraulics Laboratory, Department of Civil Engineering, University of Saskatchewan. The model pipes were 107 mm inside diameter and 2.13 m long. Standard corrugations were simulated and helix angles of 61.0 and 71.4° were tested. It was found that about 12 diameters of pipe length were required to obtain fully established flow, and a value for the development head loss of 0.2 times the velocity head was indicated. Key words: helical corrugated pipe, head losses, n values, flow establishment.

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.

Frictional Head Loss of Various Bimodal Settling Slurry Flows in Pipe

2019 ◽  
Author(s):  
Václav Matoušek ◽  
Robert Visintainer ◽  
John Furlan ◽  
Anders Sellgren
Keyword(s):  
Liquid Fraction ◽  
Fine Sand ◽  
Head Loss ◽  
Data Set ◽  
Frictional Loss ◽  
Head Losses ◽  
Granite Rock ◽  
Carrier Liquid ◽  
Four Component Model ◽  
The Individual

Abstract Pipe flows of bimodal settling slurries exhibit frictional head losses quite different from those determined simply as a sum of loss contributions by the individual fractions. Mechanisms governing flow friction and resulting from an interaction of grains of different fractions in transported slurry are not well understood. This makes a prediction of the frictional head loss in flows of bimodal slurries with Newtonian carrier uncertain. An extensive experimental campaign was conducted in GIW Hydraulic Laboratory in 2016 with slurries of four narrow graded fractions of the virtually same grain densities and very different grain sizes (carrier-liquid fraction, pseudo-homogeneous-, heterogeneous-, and stratified fractions). Besides testing of the individual fractions, different combinations of the fraction mixtures (bimodal, three- and four-component) were tested as well. In our previous work published in 2018, we employed experimental results for bimodal slurry composed of coarse granite rock (the stratified fraction) and fine sand (the pseudo-homogeneous fraction) to analyze the observed considerable reduction of the frictional head loss caused by an addition of the fine sand to the granite rock slurry. In this work, we extend our analysis to the other bimodal slurries composed of permutations of the four fractions (in total 3 additional bimodal slurries) with a major objective to identify possible mechanisms leading to a modification of the frictional head loss due to an addition of a finer fraction to a coarser mono-disperse slurry, and to quantify this effect for the purposes of a predictive four-component model (4CM). The investigation shows that the frictional loss of bimodal slurry is always smaller than the theoretical loss obtained as the sum of losses of the fractions, although the massive reduction observed in the slurry composed of the stratified rock and fine sand is not observed in any other bimodal slurry. The investigation also suggests that the friction effect obtained by the finer fraction addition is due to different mechanisms for different bimodal slurries although all mechanisms are associated with altering mechanical friction due to granular contacts. It is shown that the observed effects can be well reproduced by the friction loss model 4CM, calibrated by the experimental data set from the 203-mm pipe and validated by the data set from the 103-mm pipe.

Influence Experiment for the Spacing Distance of Orifice Plates to Local Resistance Coefficient in the Pressure Delivery Pipeline

2015 ◽  
Vol 744-746 ◽  
pp. 1092-1100 ◽  
Author(s):  
Lin Li ◽  
Sheng Jin ◽  
Zhao Liang Bai
Keyword(s):  
Resistance Coefficient ◽  
Head Loss ◽  
Relative Distance ◽  
Local Resistance ◽  
Water Losses ◽  
Head Losses ◽  
Water Head ◽  
Local Resistance Coefficient ◽  
Local Water ◽  
Maximal Relative Error

In order to research the influence rule of the spacing distance between orifice plates to the local resistance coefficient and total local water head losses , carried out the experiment research through set the two different relative distance of orifice plates in the pressure delivery pipeline. The experimental results showed that: When the relative distance, the results of total local water head losses calculated by the traditional hydraulics formula with the real measured data, the maximal relative error was less than 3%. This shown that when the relative distance was big, it was no necessary to consider the influence of the relative distance between orifice plates. However, when the relative distance, the real measured data of the total local water losses was much smaller than the calculated data by the traditional calculation formula, the maximal relative error was reached 239.5%. It was explained that when the relative distance was relative small, existed the adjoining influence between orifice plates, so the total local water losses by the multi-orifice plates was not equal to the sum of each water head loss by the single orifice plate, and the total local head loss was not necessarily increased with the number of orifice plates increasing. Whether or not the increasing total local water head losses was closely related with the relative distance of the orifice plates. The traditional local water head loss calculation formula in the hydraulics should be corrected and modified.

scholarly journals Head Losses of Horizontal Bar Racks as Fish Guidance Structures

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 475 ◽  
Author(s):  
Julian Meister ◽  
Helge Fuchs ◽  
Claudia Beck ◽  
Ismail Albayrak ◽  
Robert M. Boes
Keyword(s):  
Flow Field ◽  
Fish Passage ◽  
Head Loss ◽  
Hydraulic Performance ◽  
Velocity Fields ◽  
Hydropower Plant ◽  
Protection Measures ◽  
Head Losses ◽  
Hydropower Plants ◽  
Fish Protection

Horizontal bar racks have been used as trash racks at hydropower plants since the 1920s. With the installation of the first horizontal bar rack bypass system at a hydropower plant as a downstream fish passage facility in 2006, these racks rapidly gained importance as fish protection measures. Since then, they have been installed at more than 100 small- to medium-sized hydropower plants in Europe. Despite the large number of installed racks, systematic investigations of the head losses and velocity fields were missing. On the basis of detailed hydraulic experimentation with a large number of rack parameters and including up-to-date foil-shaped bars, the layout of horizontal bar racks and their hydraulic performance were assessed in the current study. This paper reports the results of the rack head loss investigation, whereas the accompanying paper entitled Velocity Fields at Horizontal Bar Racks as Fish Guidance Structures focuses on the up- and downstream velocity fields. By applying foil-shaped bars instead of rectangular bars, the loss coefficient was reduced by more than 40%, depending on the rack configuration. Bottom and top overlays are used to increase the guidance efficiency for fish, sediments, and floating debris. However, the altered flow field results in increased head losses. A new set of equations is proposed to predict head losses for current horizontal bar racks, including overlays for various hydropower plant layouts. The predictions are compared to literature data.

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