scholarly journals Effect of allowable flow-rate variation and local head loss on maximum length of non-pressure compensated drip tape

2021 ◽  
Vol 16 (2) ◽  
pp. 1
Author(s):  
Luiz Antonio de Andrade ◽  
João Carlos Cury Saad ◽  
Bruno Marcos Nunes Cosmo ◽  
João Victor Costa ◽  
Willian Aparecido Leoti Zanetti
Keyword(s):  
Flow Rate ◽  
Lateral Line ◽  
Line Length ◽  
Head Loss ◽  
Maximum Length ◽  
Rate Variation ◽  
Small Decrease ◽  
Water Application ◽  
Operational Costs ◽  
Lateral Lines

A challenge for the design of drip irrigation systems with non-pressure compensated emitters is to increase the maximum length of the lateral lines without significantly reducing water application uniformity. This work evaluated the effect of the flow-rate variation and the local head loss in the maximum length of drip tape with a non-pressure compensated flat emitter. The tests were carried out in a laboratory, using a collapsible drip tape non-pressure compensated in three 50-meter segments. The production line was configured to generate drip tapes without insertion of emitters and with closed emitters (0.30 m spacing). The experimental local head loss was compared with the Darcy-Weisbach equation's estimates using the Blasius friction factor. In the sequence, simulations were generated for the flow-rate variations of 10 and 20% for the emitter spacings of 0.30, 0.40, and 0.50m. The results showed that the local head loss had little influence on the lateral line's maximum length, generating variations of 2.5% on average. However, increasing the allowable flow rate variation from 10 to 20% resulted in a 34% increase in the lateral line maximum length. Also, the reduction in uniformity coefficients was less than 5%, enabling the indexes to remain above 90%. The adoption of higher flow rate variation values allowed gains in the lateral line length with a small decrease in uniformity, making it an alternative to reduce design and operational costs.

scholarly journals OTIMIZAÇÃO DO DIMENSIONAMENTO HIDRÁULICO DE UMA SUBUNIDADE DE IRRIGAÇÃO LOCALIZADA

Irriga ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 697-703
Author(s):  
Fernanda Oliveira Silva ◽  
João Batista Tolentino Júnior
Keyword(s):  
Flow Rate ◽  
Lateral Line ◽  
Hydraulic Modeling ◽  
Head Loss ◽  
Mean Flow ◽  
Santa Catarina ◽  
Rate Condition ◽  
Hydraulic Design ◽  
Caixa Postal ◽  
E Mail

OTIMIZAÇÃO DO DIMENSIONAMENTO HIDRÁULICO DE UMA SUBUNIDADE DE IRRIGAÇÃO LOCALIZADA     FERNANDA OLIVEIRA DA SILVA1 E JOÃO BATISTA TOLENTINO JÚNIOR2   [1] Aluna de Pós-Graduação do Programa de Pós-Graduação em Ecossistemas Agrícolas e Naturais, Universidade Federal de Santa Catarina, Rodovia Ulysses Gaboardi, Km 3, Caixa postal 101, CEP 89520-000, Curitibanos, SC, Brasil. E-mail: [email protected] 2 Professor Adjunto, Departamento de Agricultura, Biodiversidade e Florestas, Universidade Federal de Santa Catarina, Rodovia Ulysses Gaboardi, Km 3, Caixa postal 101, CEP 89520-000, Curitibanos, SC, Brasil. E-mail: [email protected]     1 RESUMO   O dimensionamento do sistema de irrigação é limitado pela uniformidade, e consequentemente, pela perda de carga e topografia da área. Uma das principais tarefas do dimensionamento hidráulico de um sistema de irrigação por gotejamento é determinar as características geométricas de diâmetro da tubulação, a pressão no sistema e a uniformidade em fase de projeto. Neste trabalho, utilizou-se o método do backstep para determinar a vazão, perda de carga e pressão no sistema. O modelo foi desenvolvido para atender condições sem declividade, em aclive e em declive. Aplicou-se o método da bisseção para otimizar o dimensionamento hidráulico para uma única linha lateral ou para uma subunidade de irrigação por gotejamento. Determinou-se o diâmetro interno da linha lateral e de derivação para atender a uma uniformidade de distribuição de água acima de 90%. Definiu-se a pressão no final da linha lateral e de derivação para atender a condição de vazão média requerida nos emissores. Com o avanço da tecnologia, consegue-se implementar em linguagem computacional equações complexas e chegar a um ótimo dimensionamento hidráulico. As equações foram implementadas em linguagem R, no formato de função, e mostraram ser uma ferramenta rápida e simples para o dimensionamento hidráulico de sistemas de irrigação.   Palavras-chave: backstep, bisseção, modelagem hidráulica.       SILVA, F. O. E TOLENTINO JÚNIOR, J. B. OPTIMIZATION OF HYDRAULIC DESIGN OF A MICROIRRIGATION SYSTEM     2 ABSTRACT   The design of the irrigation system is limited by the uniformity and, consequently, by the head loss and topography of the area.  One of the main tasks of the hydraulic design of a microirrigation system is to determine the geometric characteristics of pipe diameter, the pressure in the system and uniformity in the design phase.  In this work, the backstep method was used to determine the flow rate, head loss and pressure in the system. The model was developed to meet conditions without slope, uphill and downhill. The bisection method was used to optimize the hydraulic design for a single lateral line or to a microirrigation subunit. The inner diameter of the lateral line and the manifold was determined to meet a water distribution uniformity over 90%. The pressure was defined at the end of the lateral line and manifold to meet the mean flow rate condition required in the emitters. With the advancement of technology, it is possible to implement computational language complex equations and reach a great hydraulic design. The equations were implemented in the R language, in function format, and proved to be a fast and simple tool for the system hydraulic dimensioning of irrigation.    Keywords: backstep, dissection, hydraulic modeling.

scholarly journals Pressure compensating microsprinklers using microtube as a flow controller

2016 ◽  
Vol 36 (1) ◽  
pp. 36-45
Author(s):  
Alexsandro C. dos Santos Almeida ◽  
Ceres D. G. C. de Almeida ◽  
Tarlei A. Botrel ◽  
José A. Frizzone
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Lateral Line ◽  
Water Distribution ◽  
Pressure Head ◽  
Pressure Variation ◽  
Rate Variation ◽  
Flow Uniformity ◽  
Random Manner ◽  
Distribution Uniformity

ABSTRACT Microsprinkler non-pressure compensating nozzles usually show water flow variation along the lateral line. This study aimed at adapting microtubes into non-compensating system of microsprinklers previous installed in the field, as a self-compensated nozzle, to improve the flow uniformity along the lateral line. Microtubes were adapted to three types of commercial microsprinklers. Tests were conducted, both in the laboratory and in field, to evaluate the microsprinkler performance at four different flows (40, 50, 60 and 70 L h-1) under pressure head range from 75 to 245 kPa. Nozzles presented coefficient of flow-rate variation (CVq) lower than 5.5% and distribution uniformity (DU) greater than 95%, which are classified as excellent. The original spatial water distribution of the microsprinkler did not change by using microtube as a nozzle. This device adapted to non-pressure compensating microsprinklers are functional and operate effectively with flows ranging up to 70 L h-1. Small variations at microsprinkler flows along the lateral line can occur, however, at random manner, which is common for pressure-compensating nozzles. Therefore, the microtube technique is able to control pressure variation in microsprinklers.

scholarly journals Iterative calculation of local head loss coefficient of emitters in lateral lines

2021 ◽  
Vol 25 (5) ◽  
pp. 291-296
Author(s):  
Giuliani Prado ◽  
Rafael R. Bruscagin ◽  
Adriano C. Tinos ◽  
Edmilson C. Bortoletto ◽  
Denise Mahl
Keyword(s):  
Lateral Line ◽  
Pressure Head ◽  
Head Loss ◽  
Loss Coefficient ◽  
Inlet Pressure ◽  
Head Loss Coefficient ◽  
Step Procedure ◽  
Total Head ◽  
Lateral Lines ◽  
Rigid Pvc

ABSTRACT This study aimed to iteratively set the local head loss coefficient of the Naan® micro-sprinkler, model 7110 Hadar, installed in a lateral irrigation line. To evaluate the total head loss along the lateral line, tests were performed using a rigid PVC pipe with an inner diameter of 15.8 mm, 12 m in length, and 24 micro-sprinklers inserted along the pipe, regularly spaced 0.5 m. In the tests carried out for four micro-sprinkler nozzle diameters (0.9, 1.0, 1.1, and 1.2 mm) and six inlet pressure head values (5, 10, 15, 20, 25, and 30 m) in the line, the pressure head difference between inlet and outlet in the pipe and the discharge of each emitter along the pipe were measured. The head loss computation was performed by the step-by-step procedure, starting from the downstream end to the upstream end of the line; since varying the local head loss coefficient values iteratively, the total head loss measured in the tests was equal to the calculated. For the different working conditions of the inlet pressure head and the micro-sprinkler nozzle diameter, the local head loss coefficient had values from 0.051 to 0.169. Relating the discharge values measured and estimated along the lateral line, the confidence coefficient of 0.9991 was verified, and the calculation procedure was considered optimal.

scholarly journals DESEMPENHO DE GOTEJADORES COM USO DE ESGOTO DOMÉSTICO TRATADO

Irriga ◽  
2009 ◽  
Vol 14 (2) ◽  
pp. 243-253 ◽  
Author(s):  
Talita Aparecida Pletsch ◽  
Raimundo Leite Cruz ◽  
Helton Rogério Mazzer ◽  
Érica Fabiana de Oliveira
Keyword(s):  
Flow Rate ◽  
Domestic Wastewater ◽  
Working Hours ◽  
Variation Coefficient ◽  
Pressure Curve ◽  
Rate Variation ◽  
Water Application ◽  
Flow Variation

DESEMPENHO DE GOTEJADORES COM USO DE ESGOTO DOMÉSTICO TRATADO Talita Aparecida Pletsch1; Raimundo Leite Cruz1; Helton Rogério Mazzer2; Érika Fabiana de Oliveira11Departamento de Engenharia Rural, Faculdade de Ciências Agronômicas, Universidade estadual Paulista, Botucatu, SP, [email protected] de Engenharia Civil, Universidade Federal Tecnológica Federal do Paraná, Campus de Campo Mourão, PR  1 RESUMO             O presente trabalho teve como objetivo determinar a vazão dos gotejadores, a curva relação vazão-pressão, a sua equação característica, o coeficiente de variação de vazão (CVQ), e também avaliar a uniformidade de aplicação de água, do tubo gotejador da marca Netafim, modelo Tiran 17, utilizado para a irrigação com esgoto doméstico tratado. Após 1000 horas de uso do tubo gotejador, o entupimento de gotejadores reduziu a uniformidade de aplicação de água de 98% para valores menores que 60%, e aumentou o coeficiente de variação de vazão a valores maiores que 0,29. UNITERMOS: coeficiente de variação de fabricação, reúso de água             PLETSCH, T. A.; CRUZ, R. L.; MAZZER, H. R.; OLIVEIRA, É. F. de. PERFORMANCE OF DRIPPERS USING TREATED DOMESTIC WASTEWATER  2 ABSTRACT             This paper aimed to determine the flow rate of drippers, their “flow rate-pressure” curve, their equation, their flow rate variation coefficient (VCq), as well as to evaluate the uniformity of water application of the Netafim drip pipe,Tiran17 model, used for irrigation with  domestic wastewater from treated household drain. After 1000 working hours, the blockage of some drippers decreased the uniformity of water application from 98% to lower than 60% and increased the flow variation coefficient to values higher than 0.29. KEYWORDS: flow rate variation coefficient, wastewater 

scholarly journals A MODEL FOR HYDRAULIC DESIGN OF IRRIGATION LATERAL LINES

2020 ◽  
Vol 28 ◽  
pp. 140-147
Author(s):  
João Batista Tolentino Júnior ◽  
Fernanda Oliveira da Silva
Keyword(s):  
Flow Rate ◽  
Lateral Line ◽  
Least Squares Method ◽  
Linear Equations ◽  
Pressure Head ◽  
Pipe Diameter ◽  
Step Method ◽  
Lateral Lines ◽  
Rate Profile ◽  
The Cost

There are several models for hydraulic designs and optimization of lateral lines depending on the existing pressure head profile and flow which allows designing longer lateral lines, therefore decreasing the cost of the system implementation. A model has been developed to calculate the pressure head and required flow rate at the inlet of lateral line using the back step method. A set of equations was implemented in an algorithm in the R language. For the calculations, the following variables must be provided: pressure head at the end of the lateral line (Hend), coefficients K and x of the characteristic equation (flow-pressure) of the emitter, pipe diameter (D), emitter spacing (Se) and number of emitters (Ne). For the evaluation of the model, the pressure head at the end of the lateral line, the pipe diameter and the number of emitters were varied within the established limits. Relationships between these variables were established by regression analysis using the least-squares method. The model shown in the study was suitable for the calculation of the pressure head and flow rate profile along the lateral line. The power, plateau, exponential and linear equations were adjusted to describe these relationships. These equations can help in the design of irrigation systems by simplifying the procedures in order to meet the design criteria. Also, the proposed equations allow evaluation of the systems still in the design phase.

scholarly journals COMPOSIÇÃO DE PERFIS RADIAIS DE DISTRIBUIÇÃO DE ÁGUA DE ASPERSORES

Irriga ◽  
2009 ◽  
Vol 14 (1) ◽  
pp. 41-53 ◽  
Author(s):  
Giuliani Do Prado ◽  
Alberto Colombo
Keyword(s):  
Key Words ◽  
Flow Rate ◽  
Linear Relation ◽  
Water Distribution ◽  
Test Bench ◽  
Application Rate ◽  
Water Application ◽  
Irrigation Uniformity ◽  
Nozzle Configuration ◽  
Composition Process

COMPOSIÇÃO DE PERFIS RADIAIS DE DISTRIBUIÇÃO DE ÁGUA DE ASPERSORES  Giuliani do Prado; Alberto ColomboDepartamento de Engenharia, Universidade Federal de Lavras, Lavras, MG, [email protected]  1 RESUMO Este trabalho descreve um procedimento de composição do perfil radial de aspersores que operam com dois bocais. Foram determinados na bancada de ensaios de aspersores da Universidade Federal de Lavras, em Lavras/MG, os valores de vazão e perfil radial do aspersor PLONA-RL250 operando, individualmente, com os bocais principais 14 e28 mme com os bocais auxiliares 5, 6 e7 mm, e operando, nas diferentes seis combinações de bocal auxiliar e principal do aspersor, sob cinco pressões de serviço (292, 392, 490, 588 e 696 kPa). No processo de composição do perfil radial realizado, ajustando a vazão dos bocais auxiliar e principal, operando individualmente, a vazão do aspersor operando com o conjunto de bocais auxiliar e principal, verificou-se um coeficiente de determinação médio de 88,57% entre as intensidades de precipitação adimensionais dos perfis radiais compostos com os perfis radiais do conjunto. Na relação linear, ajustada, entre os valores de uniformidade de equipamentos autopropelidos de irrigação, obtidos com os perfis radiais compostos e do conjunto, a inclinação da reta foi igual a 44°12’com um erro relativo médio de 2,34%. Estes resultados mostram que o procedimento de composição do perfil radial de aspersores não influencia, de maneira significativa, na uniformidade de aplicação de água de aspersores. UNITERMOS: bocais do aspersor, vazão do aspersor, uniformidade de irrigação.  PRADO, G. DO; COLOMBO, A. SPRINKLER WATER DISTRIBUTION COMPOSITIONS  2 ABSTRACT This paper described a procedure to compose a sprinkler pattern for a sprinkler that operates with two nozzles. To compose the pattern, discharge values and patterns of the PLONA-RL250 sprinkler were determined at the sprinkler test bench of the Universidade Federal de Lavras, in Lavras/MG. The tests were conducted with all possible combinations using 14mm and28 mmmain nozzles and the 5, 6 and7 mmauxiliary nozzles as well as with each nozzle functioning individually. Five working pressures (294, 392, 490, 588 and 686 kPa) were used for each nozzle configuration. In the pattern composition process, by adjusting the main and auxiliary nozzle discharges operating individually, and by adjusting  the sprinkler discharge operating with the corresponding pair of main and auxiliary nozzles, it was verified that the average determination coefficient was 88.57% between the dimensionless water application rate of the composed and pair patterns. In the adjusted linear relation, between the uniformity values of a travel irrigation machine obtained from the composed and pair patterns, the inclination was 44° 12' with an average relative error of 2.34%. These results show that the procedure to compose a sprinkler pattern for sprinklers does not influence significantly the water application uniformity of sprinklers. KEY WORDS: sprinkler nozzles, sprinkler flow rate, irrigation uniformity

scholarly journals Cast Iron Cooling Rate Variation Using Cooling Channels: A Numerical Approach

2021 ◽  
pp. 29-35
Author(s):  
Olumide Adewole Towoju
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Cooling Rate ◽  
Flow Rate ◽  
Numerical Approach ◽  
Cooling Curve ◽  
Rate Variation ◽  
Cooling Fluid ◽  
Cooling Channels ◽  
The Impact

The cooling rate of molten cast iron can make or mar it. The cooling rate plays a significant role in the resulting mechanical properties of cast iron. It determines the grain growth and size. The mechanical properties of cast iron variation along its length are achieved either with the use of different mold materials or by sectioning to ensure varied cooling rates. Mechanical properties can, however, also be varied along its length without any of these adopted methods by the incorporation of cooling channels in the mould. This study seeks to expand the frontier of this concept with the use of different cooling fluids and fluid flow rate, and numerically investigate the impact on the cooling rate of gray cast iron (class 40). The cooling curve for the cast iron was impacted by the use of different cooling fluids with the attainment of the desired mechanical properties with the selection of an appropriate cooling fluid. Also, the flow rate of the cooling fluid has an impact on the cast iron cooling rate.

scholarly journals Influence of Particle and Grain Size on Sand Filtration: Effect on Head Loss and Turbidity

2020 ◽  
Vol 8 (2) ◽  
pp. 36
Author(s):  
Racha Medjda Bouchenak Khelladi ◽  
Abdelghani Chiboub Fellah ◽  
Maxime Pontié ◽  
Fatima Zohra Guellil
Keyword(s):  
Particle Size ◽  
Flow Rate ◽  
Granular Media ◽  
Particle Concentration ◽  
Head Loss ◽  
Sand Filtration ◽  
Circular Column ◽  
Filter Performance ◽  
Filter Operation ◽  
Suspended Matters

Sand filtration is an eco-friendly method to treat either drinking water or wastewater ; it requires only natural granular media. It is also easy to use and to maintain ; the only problem they face is clogging that affects filter performance, that can be detected when head loss or turbidity increase. The purpose of this work is to see what are the factors that influence the performance of filter operation, for this, we used a pilot consisting on a circular column filled with sand (from South Algeria), where various parameters were tested; pressure, flow rate, sand granulometry, suspended matters and particle concentration of the water which is filtered. After eighteen weeks of operation, we have found that head loss increases by decreasing granulometry and increasing flow rate, pressure, particle size, and concentration. However, turbidity increases by decreasing particle size and increasing granulometry and particle concentration. Turbidity and head loss have different behaviour towards the same parameter; that is why it is necessary to take them into account in order to find a compromise between acceptable head loss / turbidity for a good functioning of the filter.

Theory of Self-Excited Coupled-Mode Vibration of Tainter Gates

2017 ◽  
pp. 463-497
Keyword(s):  
Flow Rate ◽  
Graphical Representation ◽  
Nodal Line ◽  
The Self ◽  
Rate Variation ◽  
Body Rotation ◽  
Coupled Mode ◽  
Bending Mode ◽  
Mode Vibration ◽  
Vibration Mechanism

In general, any mechanism that produces an unbalanced moment may also serve to initiate a rigid body rotation of a Tainter gate about the trunnion pin. From the modal analysis testing on an intact Folsom Dam Tainter gate, and an understanding of the concepts of flow-rate variation pressure and push-and-draw pressure presented in Chapters 4 and 5, respectively, a conceptual model of the vibration mechanism can be formulated. The whole gate rotation induces a flow-rate variation pressure and a coupled inertia torque on the skinplate, as presented in Chapter 4. Both the flow-rate-variation pressure and the inertia torque excite the skinplate to rotate in a bending mode shape about a horizontal nodal line. In the present chapter we will develop the theory behind such an instability mechanism, called the self-excited coupled-mode instability, culminating in the graphical representation of the Folsom Dam gate instability in terms of a dynamic stability criterion diagram under the conditions at which failure occurred.

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