Water distribuition characteristics and soil loss of LEPA Quad-Spray emitter nozzles

The objective of this study was to characterize water application rate, water application pattern width, flow rate, water distribution uniformity and soil loss caused by nozzles of the Low Energy Precision Aplication (LEPA) type Quad-Spray emitter. The study was carried out at the Hydraulic and Irrigation Laboratory of the Department of Engineering at the Federal University of Lavras, in Lavras, state of Minas Gerais - MG, Brazil. Twenty-two (22) LEPA Quad-Spray emitter nozzles were evaluated, with nozzle diameter ranging from 1.59 to 9.92 mm. The experimental design used was entirely randomized, with three replications.Increasing values of nozzle flow rate ranging from 77.44 up to 3,044 L h-1, were obtained with increasing nozzle diameter sizes. Application pattern width ranged from 0.56 up to 3.24m, according to nozzles diameter size. Low values of CDU (maximum of 35.73%) were observed when using the Quad-Spray nozzles. Observed average water application rates covered the range between 68.05 mm h-1 (the lowest value that was obtained with the 2.38mm nozzle) and 258.15 mm h-1 (the highest value that was observed with the 9.92 mm). Average water application rates increased in a simple non-linear function with the increase of nozzle size diameter. However, the weighted average increase in the amount of soil loss by erosion was not related to the increase of weighted average water application values.

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COMPOSIÇÃO DE PERFIS RADIAIS DE DISTRIBUIÇÃO DE ÁGUA DE ASPERSORES

Irriga ◽

10.15809/irriga.2009v14n1p41-53 ◽

2009 ◽

Vol 14 (1) ◽

pp. 41-53 ◽

Cited By ~ 4

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

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Effects of Travel Speed and Collector on Evaluation of the Water Application Uniformity of a Center Pivot Irrigation System

Water ◽

10.3390/w12071916 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1916 ◽

Cited By ~ 1

Author(s):

Yongchong Li ◽

Xin Hui ◽

Haijun Yan ◽

Diyi Chen

Keyword(s):

Cross Section ◽

Irrigation System ◽

Weighted Average ◽

Travel Speed ◽

Application Rate ◽

Water Application ◽

Center Pivot ◽

Average Water ◽

Coefficient Of Uniformity ◽

Selection Of

Water application uniformity is an important performance parameter when designing and operating an irrigation system. Performance tests of a center pivot irrigation system equipped with fixed and rotated spray plate sprinklers (FSPS and RSPS, respectively) were conducted at five travel speeds. The effects of travel speed, collector size, and setting height on water application uniformity were evaluated using Heermann and Hein’s coefficient of uniformity (CUH). The CUH was 12.7% higher for the RSPS than the FSPS and decreased as the travel speed increased. Collector size and setting height affected CUH, and CUH was higher when the collector had a large opening cross-section compared to the collector with a small opening cross-section. CUH was higher when the collector with a low setting height compared to when it a high setting height for the FSPS. However, collector setting height had no effect on CUH for the RSPS. The weighted average water application depth (Dw) decreased as the travel speed increased. Collector size had no significant effect on Dw, but Dw with a low collector setting height was larger than the values with a high collector setting height. The water application rate increased as distance from the pivot point increased and was higher for the FSPS than the RSPS. The results will improve the selection of travel speed and collector when the water application uniformity of a center pivot irrigation system is evaluated.

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Distribuição de água por microaspersor de irrigação

Ciência e Natura ◽

10.5902/2179460x40584 ◽

2020 ◽

Vol 42 ◽

pp. 19

Author(s):

Rovany André Militz ◽

Ezequiel Saretta ◽

André Luis Teles dos Santos

Keyword(s):

Water Distribution ◽

Application Rate ◽

Water Jet ◽

Nozzle Diameter ◽

Pressure Nozzle

Many factors affect the water distribution by microsprinklers, such as the pressure, nozzle diameter, geometry and environment conditions. The distribution is characterized in tests under standard conditions established by ISO 15084 (2004). Thus, the purpose of this work was to evaluate the microsprinkler manufactured by Brazilian company Agrojet, used to irrigate orchards in Cachoeira do Sul. Microsprinklers used in the tests were equipped with yellow nozzle which has 2.3 mm in diameter, and operating at pressure of 147 kPa (21.5 psi). A grid of collectors at 0.5 m apart was placed around the microsprinkler to capture water during 1 h. The highest application rate throughout the radii was detected near the microsprinkler, and the distribution was considered non-uniform between quadrants, due to emitter geometry. There was also a gap in the application ranging from the microsprinkler to the end of its radius as a result of the frame that holds the rotor, which is thick and forms an obstacle to the water jet. Therefore, the water distribution was not satisfactory. Even so, aligning the microsprinkler frame to the irrigated tree might be a solution to minimize such effects in the non-uniform application.

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ELEVATED MICROSPRINKLER BENEFITS CITRUS TREES IN A SEVERE ADVECTIVE FREEZE

HortScience ◽

10.21273/hortsci.25.9.1137a ◽

1990 ◽

Vol 25 (9) ◽

pp. 1137a-1137

Author(s):

Larry R. Parsons ◽

T. Adair Wheaton

Keyword(s):

Application Rate ◽

Water Application ◽

Spray Application ◽

Application Rates ◽

Old Trees ◽

Freeze Protection ◽

Overhead Sprinkler ◽

Citrus Trees

Undertree microsprinkler irrigation has protected 1 or 2 year old trees to a height of 1 meter during severe advective freezes. During the severe December 1989 freeze, microsprinklers elevated to 0.9 meter protected 5 year old citrus trees to a height of 2 meters. Limb breakage due to ice loading was negligible. Protection was achieved with water application rates less than half that required by some overhead sprinkler models. Survival is attributed to 1) continuous spray from the microsprinkler rather than periodic spray from a rotating overhead sprinkler, and 2) effective localized application rate on branches intercepting spray is more than average overall spray application rate. Elevated microsprinklers provide freeze protection to a greater height and allow for more rapid post-freeze recovery.

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Centre-pivot irrigation system design for uniform water application rate

10.5194/egusphere-egu2020-2711 ◽

2020 ◽

Author(s):

Giorgio Baiamonte ◽

Mustafa Elfahl ◽

Giuseppe Provenzano

Keyword(s):

System Design ◽

Irrigation System ◽

Design Procedure ◽

Application Rate ◽

Water Application ◽

Irrigation Systems ◽

Flow Rates ◽

Irrigated Area ◽

Application Rates ◽

Irrigation System Design

In the last few decades, the use of centre-pivot irrigation systems has significantly increased, since it makes farming easier, is more efficient and less time-consuming compared to the other irrigation systems. Several studies have been focused on the hydraulics of the centre-pivot systems. Standard high-pressure impact sprinklers or low-pressure spray sprinklers or Low Energy Precision Application (LEPA) systems are generally mounted on the pipeline.To ensure the uniformity of water application, the centre-pivot design requires increasing the flow rates along the lateral, because the sprinklers farther from the pivot move faster, and therefore their instantaneous application rates must be greater. Thus, the irrigated area under a centre-pivot system expands substantially with increasing system length. To irrigate the increased area by maintaining constant the application intensity, the manufacturers propose: i) to increase the flow rates of equally spaced sprinklers, ii) to gradually decrease the spacing of equal-flow sprinklers along the centre-pivot lateral, and iii) to use semi-uniform spacing, which is a combination of the first two methods.However, the most common centre-pivot systems have equally spaced sprinklers with increasing flow rates (nozzle sizes) along the lateral, which is probably the easiest method from a practical point of view. Although many definitions and design procedures can be found in the technical literature, a universally accepted design procedure has not yet been found. In fact, the issue of centre-pivot irrigation system design is widely debated and there is still a need for simple, yet adaptive designing guidelines for farmers using these systems, specifically to maximize water use efficiency.This study presents an alternative design procedure of centre-pivot irrigation system allowing to set favourable water application rates. First, the sprinklers&#8217; spacing distribution corresponding to a fixed irrigated area along the radial direction is derived. According to this outcome, the results showed that sprinkler characteristics and/or pipe diameter need to be varied along the lateral, based on the desired and uniform water application rate. Then, for a practical case, an application based on the proposed hydraulic design procedure was performed and discussed.

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Effect of Pulsating Pressure on Water Distribution and Application Uniformity for Sprinkler Irrigation on Sloping Land

Water ◽

10.3390/w11050913 ◽

2019 ◽

Vol 11 (5) ◽

pp. 913 ◽

Cited By ~ 1

Author(s):

Lin Zhang ◽

Boyang Fu ◽

Naiwang Ren ◽

Yu Huang

Keyword(s):

Distribution Pattern ◽

Flow Rate ◽

Complex Terrain ◽

Water Distribution ◽

Constant Pressure ◽

Sprinkler Irrigation ◽

Water Application ◽

Uniformity Coefficient ◽

Sloping Land ◽

Distribution Uniformity

Crops are highly susceptible to drought in sloping land. Due to its good adaptability to complex terrain, sprinkler irrigation is one of the commonly used methods for sloping land. To improve water application uniformity for sprinkler irrigation on sloping land, an experiment was conducted on an artificial slope to determine the effects of pulsating versus constant pressure on sprinkler flow rate, radius of throw, water distribution pattern, and water application uniformity. Compared with sprinkler flow rate and water distribution uniformity at constant pressure, sprinkler flow rate was not reduced, but water distribution uniformity for a single sprinkler was improved due to the decreased uphill throw, downhill throw and the ratio of downhill throw to uphill throw at pulsating pressure. The Christiansen Uniformity Coefficient (CU) value of water distribution for a single sprinkler at pulsating pressure was about 10% higher than that of constant pressure. When water distribution of single sprinkler overlapped with rectangular arrangement, CU values for pulsating pressure were on average 4.06% higher than those for constant pressure with different sprinkler spacings. Thus, pulsating pressure is recommended for use in sprinkler irrigation on sloping land to improve water application uniformity.

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Effects of Plate Structure and Nozzle Diameter on Hydraulic Performance of Fixed Spray Plate Sprinklers at Low Working Pressures

Transactions of the ASABE ◽

10.13031/trans.13958 ◽

2021 ◽

Vol 64 (1) ◽

pp. 231-242

Author(s):

Rui Chen ◽

Hong Li ◽

Jian Wang ◽

Chao Chen

Keyword(s):

Water Distribution ◽

Sprinkler Irrigation ◽

Hydraulic Performance ◽

Nozzle Diameter ◽

Water Application ◽

Working Pressure ◽

Plate Structure ◽

Irrigation Uniformity ◽

Application Depth ◽

Peak Value

HighlightsThe hydraulic performance of fixed spray plate sprinklers (FSPS) was evaluated at low working pressures.The effects of geometric structure on the hydraulic performance of FSPS were studied.A model was developed for estimating the application depth and uniformity of FSPS under a linear-move system.The recommended values of the most effective sprinkler combination spacing for FSPS are given.Abstract. Reducing the working pressure of sprinklers can effectively reduce the energy consumption of sprinkler irrigation systems. Fixed spray plate sprinklers (FSPS) have a simple structure, and their working pressure has potential to be reduced to 40 kPa. To evaluate the hydraulic performance of FSPS at low pressure, an experiment was conducted to investigate the effects of working pressure, plate structure, and nozzle diameter on sprinkler flow rate, wetted radius, and water application distribution. Two plates (FSPSB and FSPSY) and five nozzles were used in the tests. The cumulative water application depth and irrigation uniformity coefficient were calculated under a linear-move system. The results show that sprinklers with larger nozzle diameters and higher working pressures produce greater coefficients of discharge. The wetted radius gradually increases with the increase in working pressure and nozzle diameter. Two empirical equations for estimating the wetted radius of the two plates are proposed. The FSPSB has a concave trajectory structure that produces a longer wetted radius than the FSPSY, which has a flat trajectory structure. Along the wetted radius, the water application rate increases and then decreases, with a peak value at a certain distance. For the FSPSB, the peak rate of water application decreases with increasing working pressure. However, the FSPSY shows the opposite trend, with the maximum peak value occurring at the highest working pressure of 250 kPa. The water distribution for a single FSPSB sprinkler is discrete due to the greater water dispersal caused by the deeper grooves in the plate. In contrast, a single FSPSY sprinkler provides a more uniform water distribution. The irrigation uniformity of the FSPSY is higher than that of the FSPSB. The recommended values for the most effective sprinkler combination spacings for FSPSB and FSPSY are given in this article. The results may be useful for selecting appropriate sprinklers in hydraulic design procedures. Keywords: Cumulative spray water depth, Irrigation uniformity, Sprinkler irrigation, Water distribution, Working condition.

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Laboratory assessment of the influence of rice straw mulch size on soil loss

Advances in Geosciences ◽

10.5194/adgeo-48-11-2019 ◽

2019 ◽

Vol 48 ◽

pp. 11-18 ◽

Cited By ~ 5

Author(s):

João L. M. P. de Lima ◽

Lara Santos ◽

Babar Mujtaba ◽

M. Isabel P. de Lima

Keyword(s):

Rice Straw ◽

Soil Loss ◽

Crop Residues ◽

High Surface ◽

Soil Surface ◽

Bare Soil ◽

Application Rate ◽

Laboratory Assessment ◽

Straw Mulch ◽

Application Rates

Abstract. Application of crop residues (mulch) over the soil surface is a common practice to control soil erosion and promote infiltration. This laboratory study aimed at investigating the effect of different rice straw mulch sizes on runoff and sediment transport. The experimental runs were conducted using a soil flume of adjustable slope and a rainfall simulator, considering bare soil and three different soil covers: 1, 2 and 5 t ha−1 application rates, for three sizes of rice straw mulch (10, 30 and 200 mm). The experimental results showed that for the same mulch application rate (by weight), the smaller mulch sizes (i.e. high surface coverage percentage) presented less soil loss. For example, 90 % soil loss reduction was achieved for smaller sizes of rice straw mulch and 80 % for the bigger size. The results of this study are an important contribution to the understanding of the soil loss process in small basins and to the definition of relevant soil conservation measures, at the plot/field scale.

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Cold Protection of Leatherleaf Fern in Shadehouses Using Water and Crop Covers

HortScience ◽

10.21273/hortsci.30.4.808a ◽

1995 ◽

Vol 30 (4) ◽

pp. 808A-808

Author(s):

Robert H. Stamps

Keyword(s):

Irrigation System ◽

Application Rate ◽

Water Application ◽

Crop Water ◽

Irrigation Systems ◽

Application Rates ◽

Weight One ◽

Frost Protection ◽

Rumohra Adiantiformis ◽

Supply Water

Six shadehouses were used in tests of irrigation rates and crop covers for cold-protecting leatherleaf fern [Rumohra adiantiformis (Forst) Ching]. Each shadehouse was equipped with two irrigation systems—one over-the-crop to supply heat and one over-the-shadehouse to supply water for sealing the openings in the shade fabric with ice. The over-the-crop irrigation system consisted of frost protection wedge-drive impact sprinklers providing water application rates of 0.30, 0.56, and 0.76 cm/h. Six-m × 9-m spunbonded polypropylene crop covers weighing 20 and 51 g·m–2 were tested. During radiation freezes, all water application rates protected immature fronds from damage. Damage during advective freezes decreased with increasing water application rate, but, even when crop covers were used in conjunction with irrigation, some damage still occurred. Temperatures under the lighter-weight cover were higher than under the heavier-weight one, probably because more water passed through the lighter cover to the crop. Water application rates had no effect on frond yield.

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Nozzle Flow Rate, Pressure Drop, and Response Time of Pulse Width Modulation (PWM) Nozzle Control Systems

Transactions of the ASABE ◽

10.13031/trans.14360 ◽

2021 ◽

Vol 64 (5) ◽

pp. 1519-1532

Author(s):

Jonathan Fabula ◽

Ajay Sharda ◽

Qing Kang ◽

Daniel Flippo

Keyword(s):

Pressure Drop ◽

Response Time ◽

Control Systems ◽

Flow Rate ◽

Pulse Width ◽

Pulse Width Modulation ◽

Application Rate ◽

Application Rates ◽

Duty Cycles ◽

Nozzle Pressure

HighlightsNozzle pressure drop varies between PWM systems at different application rates and application pressures.Change in flow rate with respect to the expected flow differs between PWM systems at different rates and pressures.There was a latency before the system reached the target application pressure.PWM systems operate for less time than the specified duty cycle, which may cause application errors.Abstract. Three PWM nozzle control systems, Capstan PinPoint II, John Deere ExactApply, and Raven Hawkeye, referred to as systems S1, S2, and S3, respectively, were used in this study. Data on nozzle pressure, boom pressure, flow rate, and response time were recorded with different duty cycles (25%, 50%, 75%, and 100%) and operating frequencies (10, 15, and 30 Hz) for two application rates (112.2 and 187.1 L ha-1) and two application pressures (275.8 and 448.2 kPa) at 1 kHz using a LabVIEW program and a cRIO data acquisition system. Results indicated that the PWM systems perform differently when operating at different application rates, pressures, duty cycles, and frequencies. Each PWM system provided a different pressure drop at the nozzle during operation. The increase in application rate and pressure increased the pressure drop. The percent change in flow rate with respect to the expected flow was also significantly different between the PWM systems, which could be due to the differences in pressure provided at the nozzle during operation. The PWM systems also showed latency before reaching the target application pressure during operation and operated for less time than the specified duty cycle at stable target pressure while also continuing to spray even after the solenoid valves had closed. The application pressure during peak and fall times and the time of stable application pressure within a cycle should be given careful consideration when selecting a PWM system, as they can contribute to application errors. Producers should also consider the pressure drop with the selected PWM system and target application rate to set up the system to apply at the desired pressure. Manufacturers mostly recommend operating PWM systems at 10 Hz. For the purpose of this study, the operating frequency of the PWM systems was set to 10 and 15 Hz for S1, to 15 and 30 Hz for S2, and to 10, 15, and 30 Hz for S3. Producers should expect differences in pressure drop, stabilized pressure application time, and flow rate if they choose to operate at a higher frequency. The results of this study are only applicable to the types of nozzle bodies and nozzle tips used. The data will differ based on the dual-orifice valve coefficient equation: the larger the second orifice, the greater the pressure drop. This will affect the final orifice pressure, as well as the flow rate. This study did not address the impact of flow resistance caused by differences in the design of nozzle bodies and nozzle types. Keywords: Nozzle flow rate, Pressure drop, Pulse width modulation control modules, Response time.

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