scholarly journals Effect of Nozzle Angel & Cyclic Pressure Head Variation on Water Distribution Uniformity for Stationary Sprinkler Systems

2020 ◽  
Vol 25 (2) ◽  
pp. 84-95
Author(s):  
Esraa Younis ◽  
Haqqi Yasin
Keyword(s):  
Water Distribution ◽  
Pressure Head ◽  
Cyclic Pressure ◽  
Sprinkler Systems ◽  
Distribution Uniformity

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 Water distribution from medium-size sprinkler in solid set sprinkler systems

2016 ◽  
Vol 20 (3) ◽  
pp. 195-201
Author(s):  
Giuliani do Prado
Keyword(s):  
Clustering Analysis ◽  
Water Distribution ◽  
Test Bench ◽  
Digital Simulation ◽  
Medium Size ◽  
State University ◽  
Geometric Shapes ◽  
Sprinkler Systems ◽  
Visual Basic For Applications ◽  
Distribution Uniformity

ABSTRACT The study aimed to evaluate the water distribution from a medium-size sprinkler working in solid set sprinkler systems. Water distribution radial curves from the sprinkler operating under four nozzle diameter combinations (4.0 x 4.6; 5.0 x 4.6; 6.2 x 4.6 and; 7.1 x 4.6 mm) and four working pressures (196; 245; 294 and 343 kPa) were evaluated on the sprinkler test bench of the State University of Maringá, in Cidade Gaúcha, Paraná, Brazil. The sixteen water distribution curves were normalized and subjected to clustering analysis (K-Means algorithm), identifying the occurrence of normalized distribution curves with three different geometric shapes. A computer algorithm, in Visual Basic for Applications in Excel spreadsheet, was developed to simulate the water application uniformity (Christiansen's Coefficient - CU) from the sprinklers working with rectangular and triangular layouts in solid set sprinkler systems. For the three geometric shapes of the normalized water distribution curves, digital simulation results of water distribution uniformity for the sprinklers on mainline and lateral line spaced between 10 to 100% of wetted diameter indicated that sprinkler spacings around 50% of the wetted diameter provide acceptable CU values.

scholarly journals Effect of Pulse Drip Irrigation Duration on Water Distribution Uniformity

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2276
Author(s):  
David Lozano ◽  
Natividad Ruiz ◽  
Rafael Baeza ◽  
Juana I. Contreras ◽  
Pedro Gavilán
Keyword(s):  
Drip Irrigation ◽  
Water Distribution ◽  
Crop Yields ◽  
Irrigation System ◽  
Irrigation Schedule ◽  
Sandy Soils ◽  
Field Evaluation ◽  
Irrigation Performance ◽  
Standard Procedures ◽  
Distribution Uniformity

Developing an appropriate irrigation schedule is essential in order to save water while at the same time maintaining high crop yields. The standard procedures of the field evaluation of distribution uniformity do not take into account the effects of the filling and emptying phases of the irrigation system. We hypothesized that, in sloping sandy soils, when short drip irrigation pulses are applied it is important to take into account the total water applied from the beginning of irrigation until the emptying of the irrigation system. To compute distribution uniformity, we sought to characterize the filling, stable pressure, and emptying phases of a standard strawberry irrigation system. We found that the shorter the time of the irrigation pulse, the worse the distribution uniformity and the potential application efficiency or zero deficit are. This effect occurs because as the volume of water applied during filling and emptying phases increases, the values of the irrigation performance indicators decrease. Including filling and emptying phases as causes of non-uniformity has practical implications for the management of drip irrigation systems in sloping sandy soils.

Effect of sprinkler structure on water distribution uniformity

2012 ◽  
Vol 15 (5) ◽  
pp. 052028
Author(s):  
M Xu ◽  
H Li ◽  
C Chen ◽  
Q Tu ◽  
J P Liu
Keyword(s):  
Water Distribution ◽  
Distribution Uniformity

scholarly journals ENTUPIMENTO DE GOTEJADORES CONVENCIONAIS POR PRECIPITADOS QUÍMICOS DE CARBONATO DE CÁLCIO E MAGNÉSIO, COM QUATRO ÍNDICES DE SATURAÇÃO DE LANGELIER

Irriga ◽  
2008 ◽  
Vol 13 (4) ◽  
pp. 525-539 ◽  
Author(s):  
Ralini Ferreira de Mélo ◽  
Rubens Duarte Coelho ◽  
Marconi Batista Teixeira
Keyword(s):  
Water Distribution ◽  
Saturation Index ◽  
Operating Time ◽  
Test Conditions ◽  
Terra Preta ◽  
Langelier Saturation Index ◽  
Distribution Uniformity ◽  
Calcium And Magnesium ◽  
Saturation Indexes ◽  
Bench Testing

ENTUPIMENTO DE GOTEJADORES CONVENCIONAIS POR PRECIPITADOS QUÍMICOS DE CARBONATO DE CÁLCIO E MAGNÉSIO, COM QUATRO ÍNDICES DE SATURAÇÃO DE LANGELIER  Ralini Ferreira de Mélo1; Rubens Duarte Coelho2; Marconi Batista Teixeira21Escola Agrotécnica Federal de Vitória de Santo Antão, Propriedade Terra Preta, Vitória de Santo Antão, PE, [email protected] de Engenharia Rural, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP  1 RESUMO Com o objetivo de avaliar a influência da indução forçada de precipitados químicos à base de carbonatos de cálcio e magnésio no coeficiente de variação e uniformidade de distribuição de água, foi realizado um ensaio no Laboratório de Irrigação da ESALQ/USP, utilizando-se quatro índices de saturação de Langelier (ISL): ISL -2,268; ISL 0,469; ISL 1,156 e ISL 1,439. Em cada ensaio com um determinado ISL, foram utilizados oito tipos de gotejadores convencionais, instalados em uma bancada com11 mde comprimento. As obstruções observadas nos gotejadores, tanto parciais como totais decorrentes do tempo de funcionamento, resultaram em aumento do coeficiente de variação e redução drástica da uniformidade de distribuição de água. Para as condições de ensaio realizado, observou-se que o índice de saturação de Langelier não deve ser usado como único parâmetro para prever a obstrução dos gotejadores. UNITERMOS: irrigação localizada, cálcio e magnésio, Índice de Saturação de Langelier.  MÉLO, R. F.  de; COELHO, R. D.; TEIXEIRA, M. B. CLOGGING OF A COMMERCIAL DRIPPERS BY CALCIUM AND MAGNESIUM PRECIPITATES USING FOUR LANGELIER SATURARION INDEXES  2 ABSTRACT An essay was carried out in the laboratory of irrigation at ESALQ/USP   to evaluate the effect of calcium and magnesium precipitates on the variation and uniformity coefficients in irrigation drippers. Four Langelier saturation indexes (LSI) (-2,268; 0,469; 1,156; 1,439) and eight commercial drippers were used. They were installed on an 11m bench testing apparatus. Both partial and total obstructions of the drippers were observed over the operating time increasing the variation coefficient and reducing the water distribution uniformity. Within the test conditions, LSI should not be used as a single parameter to estimate dripper clogging. KEY WORDS: drip irrigation, calcium and magnesium, Langelier saturation index

scholarly journals Linear model of water movements for large-scale inverted siphon in water distribution system

2019 ◽  
Vol 21 (6) ◽  
pp. 1048-1063 ◽  
Author(s):  
Mao Zhonghao ◽  
Guan Guanghua ◽  
Yang Zhonghua ◽  
Zhong Ke
Keyword(s):  
Linear Model ◽  
Distribution System ◽  
Water Distribution ◽  
Large Scale ◽  
Low Frequency ◽  
Virtual Water ◽  
Pressure Head ◽  
Inverted Siphon ◽  
L2 Norm ◽  
Simulation Results

Abstract This paper proposes a linear model that relates the pressure head variations at the downstream end of an inverted siphon to the flow rate variations at two ends. It divides the pressure head variations in the inverted siphon into low-frequency part and high-frequency part. The two parts are caused by the deformation of the siphon wall and the reflection of acoustic wave, respectively. In order to build a simplified relation between wall deformation and low-frequency pressure head variations, the Preissmann slot method (PSM) is adopted in this paper. The linear model can also be used in other forms of structures, such as pipes and tunnels, where a pressurized flow condition is present. In comparison with simulation results using the finite volume method, the linear model shows an L2 norm of 0.177 for a large-scale inverted siphon and 0.044 for a PVC pipe. To this end, the linear model is adopted to model a large-scale inverted siphon in a virtual water delivery system. Simulation results show that the inverted siphon can reduce water fluctuations. An equation to quantify this effect is proposed based on the linear model.

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