scholarly journals PERDA DE CARGA EM FITAS GOTEJADORAS COM EMISSORES MOLDADOS

Irriga ◽  
2019 ◽  
Vol 1 (1) ◽  
pp. 86-93
Author(s):  
Verônica Gaspar Martins Leite de Melo ◽  
Leonardo Leite de Melo ◽  
José Antônio Frizzone ◽  
Antônio Pires de Camargo ◽  
Patricia Angélica Alves Marques
Keyword(s):  
Friction Factor ◽  
Drip Irrigation ◽  
Irrigation System ◽  
Low Cost ◽  
Pressure Head ◽  
Head Loss ◽  
Operating Pressure ◽  
Relative Errors ◽  
E Mail ◽  
Pipe Inlet

PERDA DE CARGA EM FITAS GOTEJADORAS COM EMISSORES MOLDADOS     VERÔNICA GASPAR MARTINS LEITE DE MELO1; LEONARDO LEITE DE MELO2; JOSÉ ANTÔNIO FRIZZONE3; antônio pires de camargo4 E patricia algélica alves marques5   1 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 2 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 3 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 4 Faculdade de Engenharia Agrícola – UNICAMP, Av. Cândido Rondon, 501, Cidade Universitária, CEP 13083 - 875, Campinas, SP, e-mail: [email protected] 5 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected]     1 RESUMO   Embora as fitas gotejadoras sejam de baixo custo, é importante que esse material seja avaliado hidraulicamente para prover informações técnicas. O objetivo deste trabalho foi analisar a perda contínua de carga e o fator de atrito em uma fita gotejadora com emissor moldado em seu interior. O experimento foi conduzido no laboratório de irrigação da ESALQ/USP. Utilizou-se a fita gotejadora Rain-Tape® fabricada pela Rain Bird®, espessura de parede de 225 µm e emissores tipo labirinto, espaçados de 0,30 m, vazão nominal de 1 L h-1 e pressão de serviço de 55 kPa. A equação de perda de carga para regime de escoamento turbulento liso em função da vazão e da carga de pressão na entrada da fita apresenta boa habilidade para estimar a perda de carga em fitas gotejadoras com emissores moldados, sendo que 95% das estimativas apresentaram erro relativo de até 6,71%. A equação de Darcy-Weisbach pode ser utilizada para o cálculo da perda de carga desde que o diâmetro seja substituído por uma função da pressão de entrada. Para o cálculo da perda de carga, utilizando a equação de Darcy-Weisbach, o fator de atrito calculado pela equação de Blasius deve considerar um coeficiente a = 0,3408.   Palavras-chave: irrigação por gotejamento, perda de carga por atrito, fator de atrito     MELO, V. G. M. L. de; MELO, L. M. de; FRIZZONE, J. A.; CAMARGO, A. P. de; MARQUES, P. A. A. HEAD LOSS IN DRIP TAPES WITH MOLDED EMITTERS     2 ABSTRACT   Although drip tapes are low-cost equipment, proper hydraulic evaluation is important to provide information required for irrigation system design. The aim of this study was to analyze the friction head loss and the friction factor in drip tapes with molded emitters, that are employed in drip irrigation systems. Experiments evaluated the drip tape model Rain-Tape®, manufactured by Rain Bird, 225-µm wall thickness, labyrinth-type emitters, 0.30-m emitters spacing, 1 L h-1 nominal discharge and operating pressure of 55 kPa. The following conclusions were obtained: (a) the equation of head loss for smooth turbulent flow as a function of flow rate and pressure head at the pipe inlet provided good predictions of head loss in drip tapes with molded emitters, since 95% of predictions presented relative errors less than 6.71%; (b) the Darcy-Weisbach equation may be used for calculating head loss, but the pipe diameter must be replaced by a function considering the lateral inlet pressure; (c) for calculating head loss of the Rain-Tape using the Darcy-Weisbach equation, the friction factor obtained by the Blasius equation should use the coefficient a = 0.3408.   Keywords: drip irrigation, frictional head loss, friction coefficient

scholarly journals Head Loss in Thin-Walled Drip Tapes with Continuous Labyrinth

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Verônica G. M. L. Melo ◽  
Ana C. S. Araújo ◽  
Antonio P. Camargo ◽  
Leonardo L. Melo ◽  
José A. Frizzone ◽  
...  
Keyword(s):  
Friction Factor ◽  
Power Law ◽  
Low Cost ◽  
Pressure Head ◽  
Average Diameter ◽  
Head Loss ◽  
Operating Pressure ◽  
Power Law Model ◽  
Optimum Diameter ◽  
Thin Walled

Thin-walled drip tapes with continuous labyrinth have been used for irrigation of vegetables and other short-cycle crops, especially due to their low cost. The continuous labyrinths welded into the pipe inner wall affect the head loss along such emitting pipes. In addition, the flow cross section of thin-walled pipes may change due to the effects of the operating pressure, which also has consequences for the head loss. The objective of this work was to investigate experimentally the friction factor and the head loss on thin-walled drip tapes with continuous labyrinths operated under various pressures. Two models of commercial thin-walled drip tapes with continuous labyrinths were evaluated. Nonperforated samples were used to determine the head-loss equations. The equations were adjusted as a function of flow rate and pressure head at the pipe inlet. Alternatively, the diameter in the Darcy–Weisbach equation was adjusted as a function of the pressure head by a power-law model. The possibility of using a mean diameter in the Darcy–Weisbach equation was also analyzed. Experimental investigation indicated that the friction factor in the Darcy–Weisbach equation can be accurately described using a power-law model, like the Blasius equation, but characterized by a coefficient a=0.3442 for the Turbo Tape and a=0.3225 for the Silver Tape. The obtained values of a are larger than those generally used and available in the literature. The influence of the operating pressure on the pipe diameter can be neglected for the purpose of calculating the head loss. The two approaches, considering the variation of the diameter with the pressure head and considering an optimum average diameter for the calculation of head loss by the Darcy–Weisbach equation, produce similar results, allowing accurate prediction of head loss. Evaluating the proposed mathematical models, 95% of predictions presented relative errors of head loss smaller than 5%. For the Turbo Tape, the optimum diameter for the purpose of calculating the head loss is 16.01 mm, which is very close to the value indicated by its manufacturer (15.9 mm). For the Silver Drip, the optimum diameter is 15.71 mm, while the manufacturer gives a value of 16.22 mm, which produces considerable error in the calculation of head loss.

scholarly journals A field study on hydraulic performance of drip irrigation system for optimization of operating pressure

2017 ◽  
Vol 9 (4) ◽  
pp. 2261-2263
Author(s):  
Mairaj Hussain ◽  
Sudhiranjan Prasad Gupta
Keyword(s):  
Field Experiment ◽  
Field Study ◽  
Coefficient Of Variation ◽  
Drip Irrigation ◽  
Irrigation System ◽  
Pressure Head ◽  
Maximum Efficiency ◽  
Operating Pressure ◽  
Drip Irrigation System ◽  
Irrigation Technology

Drip irrigation technology will undoubtedly plays an important role in the future of the agriculture. A field experiment was conducted to evaluate the performance of drip system with five operating pressure viz. I1 (0.4 kg/ cm2), I2 (0.6 kg/cm2), I3 (0.8 kg/cm2), I4 (1.0 kg/cm2), I5 (1.2 kg/cm2). It was observed that the average discharge of drippers was 1.08 lph, 1.24 lph, 1.50 lph, 1.62 lph and 1.74 lph and emission uniformity was 80.55%, 84.89%, 86.30%, 88.88% and 90.80 in each treatment respectively and coefficient of variation was observed 0.12, 0.13, 0.12, 0.11, and 0.09. Flow component was found 0.450 and the value of k was 0.572 while R2 was observed 0.986.Based on the result it can be concluded that the operation of drip irrigation system at 1.2 kg/cm2 pressure head, gives the maximum efficiency in respect of discharge, emission uniformity and coefficient of variation.

Pressure-discharge and Hydraulic Gradient along the Lateral of the Drip Irrigation System for Okra

2019 ◽  
pp. 1-6
Author(s):  
S. Vanitha ◽  
S. Senthilvel
Keyword(s):  
Drip Irrigation ◽  
Crop Production ◽  
Water Distribution ◽  
Irrigation System ◽  
Maximum Yield ◽  
Pressure Head ◽  
Hydraulic Gradient ◽  
Operating Pressure ◽  
Irrigation Systems ◽  
Gradient Compensation

Micro irrigation system should ensure relatively same amount of water to each plant along the total length of lateral line. In general, the drip irrigation systems are low to medium operating pressure head systems with a pressure requirement in range of 0.5 kg/cm2 to 2.5 kg/cm2 depending on the area irrigated and field layout geometry. However, since these systems are pressure irrigation systems which require appropriate operating pressure heads to deliver the required rates of flow, the inevitable frictional head losses are to be compensated for maintaining uniformity in water application. Hence, the hydraulic gradient compensation needs to be achieved by some viable mechanism so that the inequality in pressure heads and discharges can be eliminated or minimized. The crop production will have its maximum yield and water use efficiency only one the water distribution uniformities at its the highest. Hydraulic gradient compensation assumes a vital role in compensating the operating pressure heads as well as the emitter discharges. The hydraulic gradient compensated drip lateral layout registered high order of water distribution uniformity in the range of 97.8% and irrigation usage efficiency in the range of 17.98 kg/ha/mm to 20.69 kg/ha/mm for 2 lph emitter arrangements.

scholarly journals DESIGN OF MICROIRRIGATION SYSTEMS IN SLOPING LANDS USING LINEAR PROGRAMMING

Irriga ◽  
2002 ◽  
Vol 7 (3) ◽  
pp. 214-225
Author(s):  
João Carlos Cury Saad ◽  
Miguel A Mariño
Keyword(s):  
Linear Programming ◽  
Annual Cost ◽  
Irrigation System ◽  
Pressure Head ◽  
Sao Paulo ◽  
São Paulo ◽  
Paulo State ◽  
Hydraulic Network ◽  
São Paulo State ◽  
E Mail

DESIGN OF MICROIRRIGATION SYSTEMS IN SLOPING LANDSUSING LINEAR PROGRAMMING[1]   João CarlosCury SaadDepartment of Rural Engineering, College of Agricultural Sciences, São Paulo State University, P.O. 237, CEP 18603-970, Botucatu, SP. E-mail: [email protected] A. MariñoDepartment of Land, Air and Water Resources and Department of Civil & Environmental Engineering, University of California, Davis, CA 95616, USA. E-mail: [email protected]    1 Summary  When the area to be irrigated has a high slope gradient in the manifold line direction, an option is to use a tappered pipeline to reduce pipe costs and keep pressure head variations within desired limits. The purpose of this paper was to develop a linear programming model to design a microirrigation system with tappered manifold lines in downhill condition, minimizing the equivalent annual cost of hydraulic network and the energy annual cost, and assuring that the maximum variation in the pressure head previously established will be observed. The input data are: irrigation system layout, cost of all hydraulic network components and energy cost. The output are: equivalent annual cost, pipeline diameter in each line of the system, pressure head in each node, and total operating pressure head. To illustrate its capability, the model was applied in a citrus orchard in Sao Paulo State, Brazil. The model proved to be efficient in the design of the irrigation system in terms of emission uniformity desired. The pumping annual cost must be considered in the microirrigation system design because it yields a lower total annual cost when compared with the same alternative without that cost.  Keywords: linear programming, optimization, slope land, micro irrigation    SAAD, J. C. C.; MARIÑO, M. A.  DIMENSIONAMENTO DE SISTEMAS DE IRRIGAÇÃO POR MICROASPERSÃO EM ÁREAS COM DECLIVIDADE UTILIZANDO PROGRAMAÇÃO LINEAR   2 Resumo  Quando a área a ser irrigada apresenta um elevado gradiente de declive na direção das linhas de derivação, uma opção de dimensionamento é o uso de tubulações com vários diâmetros para economizar no custo e também para manter a variação de pressão dentro dos limites desejados. O objetivo deste trabalho foi desenvolver um modelo de programação linear para dimensionar sistemas de irrigação por microaspersão com linhas de derivação com mais de um diâmetro e operando em declive, visando a minimização do custo anualizado da rede hidráulica e do custo anual com energia elétrica, além de assegurar que a máxima variação de carga hidráulica na linha será respeitada. Os dados de entrada são: configuração da rede hidráulica do sistema de irrigação, custo de todos os componentes da rede hidráulica e custo da energia.  Os dados de saída são: custo anual total, diâmetro da tubulação em cada linha do sistema, carga hidráulica em cada ponto de derivação e altura manométrica total. Para ilustrar a potencialidade do modelo desenvolvido, ele foi aplicado em um pomar de citros no Estado de São Paulo, Brasil. O modelo demonstrou ser eficiente no dimensionamento do sistema de irrigação quanto à obtenção da uniformidade de emissão desejada. O custo anual com bombeamento deve ser considerado no dimensionamento de sistemas de irrigação por microaspersão porque ele gera menores valores de custo anual total quando comparado com a mesma alternativa que não considera aquele custo.  UNITERMOS: programação linear, otimização, declividade, microaspersão 

scholarly journals CONCENTRATION OF SINGLE SUPERPHOSPHATE ON CLOGGING OF DRIP EMITTERS

Irriga ◽  
2018 ◽  
Vol 23 (3) ◽  
pp. 566-575
Author(s):  
Dayane Rodrigues Gonçalves ◽  
Pedro Robinson Medeiros ◽  
Elton Vieira Teles ◽  
Gabiane Souza Santos ◽  
Roberto Castro Nascimento ◽  
...  
Keyword(s):  
Flow Rate ◽  
Irrigation System ◽  
Rate Variation ◽  
Operating Pressure ◽  
Mean Flow ◽  
Single Superphosphate ◽  
Relative Flow Rate ◽  
Country Club ◽  
On Line ◽  
E Mail

CONCENTRATION OF SINGLE SUPERPHOSPHATE ON CLOGGING OF DRIP EMITTERS     DAYANE RODRIGUES GONÇALVES1; PEDRO RÓBINSON FERNANDES DE MEDEIROS1; ELTON CARLOS PEREIRA VIEIRA DE ALENCAR TELES1; GABIANE SOUZA DOS SANTOS1; ROBERTO CASTRO NASCIMENTO1 E FRANCISCO MAX FERNANDES DO NASCIMENTO2   1Colegiado de Pós Graduação em Engenharia Agrícola, Universidade Federal do Vale do São Francisco, Av. Antônio Carlos Magalhães, 510, Country Club, CEP: 48902-300, Juazeiro, BA, Brasil. E-mail: [email protected] 2Colegiado de Graduação em Engenharia Agrícola e Ambiental, Universidade Federal do Vale do São Francisco, Av. Antônio Carlos Magalhães, 510, Country Club, CEP: 48902-300, Juazeiro, BA, Brasil. E-mail: [email protected]     1 ABSTRACT   The localized irrigation systems are most suitable to fertigation uses, when compared to sprinkle, but are affected by the clogging of drip emitters, influencing the uniformity of the irrigation system. This study aims to analyze the susceptibility of on-line drippers under fertigation with single superphosphate to the clogging. This study was done at the Irrigation Laboratory of UNIVASF, Juazeiro-BA campus, Brazil. Two on-line non-pressure compensating drippers with different flow rates were used, both with the same operating pressure (150 kPa). The parameters analyzed were mean flow, relative flow rate, standard deviation, coefficient of flow rate variation, the CUC, DU, SUC and HUC, and clogging degree. The results show that the concentration used for single superphosphate showed no risk of clogging of the drip emitters during system runtime.   Keyworks: drip irrigation system, non-pressure compensating drippers, application efficiency     GONÇALVES, D. R.; MEDEIROS, P. R. F.; TELES, E. C. P. V. A.; SANTOS, G. S.; NASCIMENTO, R. C.; NASCIMENTO, F. M. F. CONCENTRAÇÃO DE SUPERFOSFATO SIMPLES NA OBSTRUÇÃO DE GOTEJADORES     2 RESUMO   Os sistemas de irrigação localizada são os mais indicados para uso na fertirrigação quando comparado com a aspersão, porém são afetados pela obstrução influenciando na uniformidade dos mesmos. Este trabalho tem como objetivo analisar a susceptibilidade ao entupimento de gotejadores tipo online sob fertirrigação com superfosfato simples. Esse trabalho foi realizado no Laboratório de Irrigação da UNIVASF, campus Juazeiro- BA. Foram utilizados dois emissores do tipo gotejadores online não autocompensantes com diferentes vazões, ambos com a mesma pressão de serviço (150 kPa). Avaliou- se os parâmetros vazão média, vazão relativa, desvio padrão, coeficiente de variação de vazão, os coeficientes CUC, CUD, CUE e CUH e grau de entupimento. Os resultados demonstram que a concentração utilizada de superfosfato simples não apresentou riscos de obstrução dos emissores durante o tempo de funcionamento do sistema.   Palavras chave: irrigação localizada, gotejadores não compensados, eficiência de aplicação

scholarly journals Performance of Disc, Conventional and Automatic Screen Filters Under Rainbow Trout Fish Farm Effluent for Drip Irrigation System

2021 ◽  
Author(s):  
Abed Mohammad Hasani ◽  
Saman Nikmehr ◽  
Eisa Maroufpoor ◽  
younes Aminpour ◽  
Jaume Puig Bargués
Keyword(s):  
Rainbow Trout ◽  
Drip Irrigation ◽  
Irrigation System ◽  
Head Loss ◽  
Fish Farm ◽  
Drip Irrigation System ◽  
Working Pressure ◽  
North West ◽  
The North ◽  
The Difference

Abstract This study aims to investigate the performance of disc, conventional screen, and automatic screen filters when rainbow trout fish effluent is used for irrigation. The experiments were performed in a fish farm, located in the north-west of Iran. The disc and conventional screen filters were tested at pressures of 150 and 300 kPa, and the automatic screen filter at 200 and 300 kPa. The filtration experiments continued until the backwashing was reached. The results showed that (1) the initial head loss of disc and conventional screen filters was 40 kPa, while for the automatic screen filter was 5 kPa. (2) In the disc filter, with increasing working pressure, the filtered volume significantly (P<0.05) increased from 9.7 to 14.5 m3 m-2 (10 kPa)-1, but for conventional and automatic screen filters, it was constant at 5.5 and 7.0 m3 m-2 (10 kPa)-1, respectively, and all of them had significant (P<0.05) differences. (3) In the disc filter, with increasing the working pressure, the filtered volume to reach backwashing significantly (P<0.01) increased from 80.9 to 104.4 m3 m-2, while in the conventional screen filter increased from 14.1 to 16.4 m3 m-2. This volume at two working pressures was 29.5 m3 m-2 for the automatic screen filter. These volumes were significantly different (P<0.01) between filters. (4) The mass retention for the disc, conventional, and automatic screen filters were 28.88, 9.11, and 7.72 g min-1 m-2, respectively and tended to increase at lower working pressures. Based on this index, the difference in the performance of the filters was significant (P<0.01). (5) Overall, the best performance was for the disc filter, and after that was the automatic screen filters, but the period of time to operate for the filters until backwashing time was less than half an hour, which is not applicable under farm conditions.

scholarly journals Development and Sensitivity Analysis of an Empirical Equation for Calculating the Amplitude of Pressure Head Loss of Oscillating Water Flow in Different Types of Pipe

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2421
Author(s):  
Kai Zhang ◽  
Baoxu Zhang ◽  
Delan Zhu
Keyword(s):  
Water Flow ◽  
Empirical Equation ◽  
Pressure Head ◽  
Head Loss ◽  
Model Parameters ◽  
Pipe Material ◽  
Efficient Operation ◽  
Pipe Networks ◽  
Different Types ◽  
Relative Errors

Low pressure oscillating water flow can reduce the investment and energy consumption of irrigation. It is also effective in reducing the clogging of an emitter and improving the spraying quality of sprinklers. In order to overcome the problem of the complex process in calculating the amplitude of the pressure head loss of oscillating water flow in different types of pipes, in this study, an empirical equation for the amplitude of the pressure head loss of oscillating water flow in different types of pipe has been developed. Further, validation experiments have been conducted to verify the accuracy of the calculated amplitudes of the pressure head loss by the empirical equation. The results show that average relative error between the measured and the calculated amplitudes of the pressure head loss by the empirical equation is 10.77%. Since the relative errors are small, it is an indication that the amplitudes of the pressure head loss calculated by the empirical equation are accurate. For the empirical equation developed in this study, the sensitivity of the model parameters has been analyzed. The results show that the amplitude of velocity, the internal pipe diameter, and the length of pipe are classified as highly sensitive. The average velocity, the period of oscillating water flow, and the modulus of elasticity of the pipe material are classified as sensitive. The thickness of the pipe wall is classified as medium sensitive. Compared with the calculation models of the existing researches, the empirical equation reduces the number of parameters required to be calculated, by which many complicated calculations are avoided, which greatly improves the computing efficiency. This is conducive to the efficient operation and management of oscillating water flow in irrigation pipe networks and also provides help for the optimal design of irrigation pipe networks.

scholarly journals Head loss in laser-perforated thin-walled polyethylene pipes for irrigation

2019 ◽  
Vol 23 (5) ◽  
pp. 317-323 ◽  
Author(s):  
Verônica G. M. L. de Melo ◽  
José A. Frizzone ◽  
Antonio P. de Camargo ◽  
Wagner W. Á. Bombardelli
Keyword(s):  
Flow Rate ◽  
Pressure Head ◽  
Head Loss ◽  
Internal Diameter ◽  
Thin Wall ◽  
Operating Pressure ◽  
Irrigation Systems ◽  
Polyethylene Pipes ◽  
Flexible Pipes ◽  
Thin Walled

ABSTRACT For reducing fixed and operational costs in pressurized irrigation systems, thin-walled polyethylene pipes with laser-perforated orifices are manufactured to operate under low pressure (up to 100 kPa). Hydraulic characterization of these materials is essential for designing irrigation systems. Considering the material elasticity and the thin wall thickness (about 200 μm), the internal diameter of these pipes may vary according to the operating pressure, resulting in changes of head losses. The purpose of this study was to analyze the head loss in flexible pipes with laser-perforated orifices, and to estimate the maximum length of laterals based on criteria of water distribution uniformity. Non-perforated pipe samples were tested to obtain equations of friction loss. Equations were fitted as a function of flow rate and pressure head at the pipe inlet, and, alternatively, the Darcy-Weisbach equation was modified considering the diameter expressed as a power-law function of pressure head. The equation of head loss as a function of flow rate and pressure head provided proper estimations and considered effects related to changes in the diameter of plastic pipes due to variations in the pressure head. The Darcy-Weisbach equation can be employed for estimating head loss in flexible pipes, whose diameter varies due to pressure, but the diameter must be calculated as a function of the pressure head at the lateral inlet.

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