scholarly journals The Development of a Calculation Model for the Instantaneous Pressure Head of Oscillating Water Flow in a Pipeline

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1583 ◽  
Author(s):  
Kai Zhang ◽  
Bo Song ◽  
Delan Zhu

Sinusoidal oscillating water flow at low pressure can improve the anti-clogging ability of an emitter in drip irrigation or the water distribution of a nozzle in sprinkler irrigation and reduce the cost and energy consumption of the irrigation system. In this study, the characteristics of instantaneous pressure head attenuation of oscillating water flow along a pipeline have been investigated. By using a complex function to solve the continuity equation and the momentum equation of a pipeline with water hammer motion and using the Darcy–Weisbach formula to estimate the head loss, a calculation model for the instantaneous pressure head of oscillating water flow along a pipeline was developed. The measured value of the amplitude of the pressure head and the average instantaneous pressure head in the experiments have been used to verify the corresponding pressure head calculated by the model. The results show that the amplitude of the pressure head and the average instantaneous pressure head decrease linearly along the pipeline. The calculated value of the amplitude of the pressure head and the average instantaneous pressure head are basically close to the corresponding measured pressure head. From the results of all the tests, the maximum relative error of the calculated and measured value of the amplitude of the pressure head along the pipeline was 9.44%. The maximum relative error of the calculated and measured value of the average instantaneous pressure head along the pipeline was 8.37%. Hence, the model can accurately predict the instantaneous pressure head of oscillating water flow along a pipe and provide a theoretical basis for the application of oscillating water flow in irrigation systems and the design of irrigation pipe networks.

2017 ◽  
Vol 2 (2) ◽  
pp. 430-438
Author(s):  
Ariswandi Putra ◽  
Ichwana Ichwana ◽  
Susi Chairani

Abstrak. Sistem irigasi curah pada penerapannya dapat menghemat air serta waktu yang dibutuhkan untuk menyiram tanaman. Sistem irigasi curah mendistribusikan air dari pompa air sebagai sumber tekanan melalui sistem perpipaan hidrolika dalam bentuk curahan air yang disemprotkan ke udara, kemudian curahan air tersebut jatuh ke tanah maupun akar-akar  tanaman. Ketinggian pipa merupakan salah satu faktor penting yang dapat menentukan kinerja sistem irigasi curah terhadap keseragaman distribusi atau penyebaran curahan air ke tanaman. Hasil penelitian ini menjelaskan bahwa ketinggian pipa memberi pengaruh terhadap semua parameter yang diamati, yakni koefisien keseragaman distribusi air (CU), laju penyiraman air dan jarak lempar air. Nilai rata-rata debit nozzle yang diperoleh adalah 3,4007 liter/menit dan nilai rata-rata laju penyiraman air 4897,032 mm/hari. Nilai koefisien keseragaman distribusi air adalah sebesar 99,017 % pada riser 15 cm, 99,015 % pada riser 20 cm dan 99,016 % pada riser 25 cm. Kemudian nilai rata-rata jarak lempar air 127,33 cm. Adapun untuk mengetahui pengaruh ketinggian pipa pada sistem irigasi curah adalah dengan menggunakan persamaan regresi linear. Maka nilai regresi linear yang dihasilkan adalah sebesar 75,4 % dari seluruh parameter yang diamati, yakni koefisien keseragaman distribusi air (CU), laju penyiraman air dan jarak lempar air. Kata kunci : Sistem irigasi curah, ketinggian pipa. Abstract. The sprinkler irrigation system in the application of bulk can save water as well as the time needed for watering plants. The sprinkler irrigation system to distribute the water from the water pump as the source pressure through the piping system hydraulics in the form of a drink of water that is sprayed into the air, then the water flow fell to the ground and the roots of plants. The riser is one of the important factors that can determine the performance of irrigation systems bulk of the uniform distribution or dissemination of water flow into the plant. The results of this study explains that the height of the pipe to give effect to all parameters were observed, namely water distribution coefficient of uniformity (CU), the rate of watering and water throwing distance. The average value obtained discharge nozzle is 3.4007 liters / min and the average value of the rate of watering 4897.032 mm / day. The coefficient of uniformity of water distribution is equal to 99.017% at 15 cm riser, the riser 99.015% 99.016% 20 cm and 25 cm on the riser. Then the average value of 127.33 cm water throwing distance. As for the height of the pipe to determine the effect on the bulk of irrigation systems is to use linear regression equation. Then the resulting linear regression value is equal to 75,4 % of all observed parameters, ie water distribution coefficient of uniformity (CU), the rate of watering and water throwing distance. Keywords : The sprinkler irrigation system, the riser.


Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2296 ◽  
Author(s):  
Yisheng Zhang ◽  
Jinjun Guo ◽  
Bin Sun ◽  
Hongyuan Fang ◽  
Delan Zhu ◽  
...  

Uniformity of water distribution plays an important role in evaluating irrigation quality. As necessities in calculating irrigation uniformity during designing a lateral-move sprinkler irrigation system (LMSIS), the water distribution patterns of individual sprinkler in motion are crucial. Considering the limitation of the experiment platform, dynamic water distribution of an isolated sprinkler is difficult to measure, especially for a fixed spray plate sprinkler (FSPS) which LMSIS has been widely equipped with in China, therefore developing a model to simulate dynamic water distribution of a moving sprinkler is necessary. The objective of this study was to develop and validate the theoretical basis for calculating water distribution characteristics of a single FSPS in translational motion applying a superposition method, and provide an optimized operation management of LMSIS. The theoretical model’s validity was verified in an indoor experiment using a Nelson D3000 FSPS in motion with 36 grooves and blue-plate spray heads. The software was programmed using the Eclipse Platform and the software was capable of simulating water distribution pattern and Christiansen uniformity coefficient (Cu). The results indicated that the water distribution simulated by the software presents three peaks of maximum application under varying conditions, and the value of water application peaks decreased as working pressure and/or mounting height increased. Conversely, the wetted diameter increased as working pressure and/or mounting height increased. Working pressure, mounting height, and sprinkler spacing each had a significant effect on the Cu. The Cu increased as working pressure and/or mounting height increased but decreased as sprinkler spacing increased. As a consequence, the model can be used to predict the relative water distribution pattern; and the Cu can be calculated with the simulated data, thus providing a tool for designing a new LMSIS.


2021 ◽  
Vol 922 (1) ◽  
pp. 012046
Author(s):  
P Satriyo ◽  
I S Nasution ◽  
D V Della

Abstract In recent decades, precision agriculture and smart farming have become promising issues particularly in the industrial revolution era 4.0. The main objective of this presented paper is to apply the optimized controlling system developed by means of Internet of things for controlling sprinkler irrigation systems used for agricultural product cultivation where in this study, we used shallot plants. The controlling systems were established by designing hardware and software used to monitor water distribution in sprinkler irrigation for onion plants during five initial days of cultivation. The result showed that controlled irrigation can optimize and monitor all plant growth indicators namely soil moisture, temperature, air humidity and water discharge and be able to carry out watering according to the desired level of soil moisture. It may conclude that a controlled sprinkler irrigation system can be applied as a part of precision agriculture practice in order to enhance production and sustainable agriculture.


Author(s):  
Xingye Zhu ◽  
Shouqi Yuan ◽  
Jianrui Liu ◽  
Xinkun Wang ◽  
Bin Cai

The resistance loss of sprinkler irrigation system is an important parameter, it has significance and practical value for studying its device characteristics. In this study, according to the selected materials and setting modes, both the pressure drop along the pipe and the local resistance loss were calculated out. The theoretical device characteristics of one sprinkler irrigation system was analyzed. A calculating schema has been carried out in order to apply the method to any sprinkling system. Experimental study was carried out for this system. Water distribution maps for the sprinklers were drawn using Matrix Laboratory (MATLAB). The hydraulic characteristics were as follow, 7.2, 3.0, 10.0 mm/h was the average, minimum, and maximum irrigated intensity, respectively. It supplied theoretical foundation for the reasonable application of sprinkler irrigation system for the future.


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

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.


Author(s):  
Juan Tandazo Garcés ◽  
Oscar Caicedo Camposano ◽  
Carlos Salas Macías ◽  
Viviana Sánchez Vásquez

Quality of subfoliar sprinkler irrigation in Theobroma Cacao L. in San Vicente farm, Los Ríos, Ecuador Resumen Se realizó la evaluación del manejo de un sistema de riego por aspersión subfoliar en el cultivo de cacao, en donde el objetivo fue valorar su comportamiento hidráulico. Se estudiaron tres presiones de trabajo de los aspersores en cinco módulos del sistema. Los parámetros evaluados fueron: presiones al inicio y final de los laterales de riego, caudales en esos mismos sitios, coeficiente de uniformidad de Christiansen, uniformidad de distribución y área regada adecuadamente. Los resultados indican que existe una variación de presión y caudal por encima de lo teórico (20% y 10%). Se evidenció que altos coeficientes de uniformidad no representan la mayor área regada adecuadamente. Las presiones de trabajo estudiadas en los aspersores aseguran altos coeficientes de uniformidad del riego, no obstante, si lo que se desea es alcanzar la mayor área adecuadamente regada se debe operar a 275,79 kPa. Palabras claves: caudal; uniformidad; presión de trabajo. Abstract The evaluation of the management of a subfoliar sprinkler irrigation system in the cocoa crop was carried out, where the objective was to evaluate its hydraulic behavior. Three working pressures of the sprinklers were studied in five modules of the system. The parameters evaluated were: pressures at the beginning and end of the irrigation sides flow at those same sites, Christiansen Uniformity Coefficient, Distribution Uniformity and Adequately Irrigated Area. The results indicate that there is a variation of pressure and flow above the theoretical, that is, of 20% and 10%. It was evidenced that high uniformity coefficients do not represent the largest area irrigated adequately. The work pressures studied in the sprinklers ensure high coefficients of uniformity of irrigation, however, if what is desired is to reach the largest area adequately irrigated, it should be operated at 275.79 kPa. Keywords: flow; uniformity; pressure head.


Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1325 ◽  
Author(s):  
Kai Zhang ◽  
Bo Song ◽  
Delan Zhu

Laterally-moving sprinkler irrigation systems under low pressure experience problems including small spraying range, low uniformity, surface runoff, and low water utilization rate. To solve these problems, experiments were carried out on a laterally-moving sprinkler irrigation system using a Nelson D3000 sprinkler (Nelson Irrigation Co., Walla Walla, WA, USA) under low pressure, sinusoidal oscillating water flow. The sprinkler intensity and impact kinetic energy intensity distribution were investigated for sprinklers both static and in motion. The test data were used to calculate combined sprinkler intensity and impact kinetic energy intensity uniformity for different nozzle spacings, and were compared with constant water pressure test results. It was found that sinusoidal oscillating water flow can effectively increase spraying range, as well as reducing the peak value of the sprinkler intensity and impact kinetic energy intensity. Within an optimal range of amplitude and nozzle spacing, sinusoidal oscillating water flow significantly improves the combined sprinkler intensity, impact kinetic energy intensity uniformity, and the spraying quality of laterally-moving sprinkler irrigation systems under low pressure conditions. When the average water pressure is 100 kPa, the optimal range of amplitude of sinusoidal oscillating flow applied to the laterally-moving sprinkler irrigation system is 50–60 kPa. When the amplitude is 50 kPa, the optimal nozzle spacing is 3.5–4 m; when the amplitude is 60 kPa, the optimal nozzle spacing is 3.5–4.5 m. The related parameters can provide a reference for the application of sinusoidal oscillating water flow in laterally-moving sprinkler irrigation systems.


2018 ◽  
Vol 8 (12) ◽  
pp. 2601 ◽  
Author(s):  
Saeed Rad ◽  
Lei Gan ◽  
Xiaobing Chen ◽  
Shaohong You ◽  
Liangliang Huang ◽  
...  

Sprinkler irrigation systems are widely used in medium and large scale farms in different forms. However less types are available to apply in small farms due to their high costs. The current study was done according to a novel cost effective design for a semi-permanent sprinkler irrigation system for small farm owners. The new layout known as Corner Pivot Lateral (CPL) was examined in irrigation test center at Lijian Scientific and Technological Demonstration Park, at Nanning city, China. CPL was implemented without a main/sub mainline pipe, by applying a single pivoting lateral at the corner of the plot that directly connected to the resource to convey water from the pump. The lateral moves around the corner using a rotating elbow in a quadrant pattern manually to cover the entire farm. A conventional semi-permanent system was applied for the same farm as reference. A cost analysis on the required components as well as annual operational costs was carried out for comparison and control. Results showed that a lower system component would be needed for the CPL method. Overall, more than a 15% capital cost reduction with 7% annual cost decrement was achieved for CPL in this experiment comparatively. The Catch can technique was applied to examine the CPL system’s efficiency and 79% water distribution uniformity around the sprinkler was obtained. This new method can encourage small estate holders to switch from traditional to pressurized systems which optimizes water application costs.


2010 ◽  
Vol 148 (2) ◽  
pp. 139-157 ◽  
Author(s):  
M. JIMÉNEZ ◽  
J. A. DE JUAN ◽  
J. M. TARJUELO ◽  
J. F. ORTEGA

SUMMARYThe main objective of the current study was to analyse how water application through a sprinkler irrigation system influences yield of onion (Allium cepa L.), taking into account water application heterogeneity and the effects on theoretical crop evapotranspiration (ETc). Field experiments were conducted on commercial onion plots, irrigated with a permanent sprinkler irrigation system, located in Albacete, Spain, over two irrigation seasons. Two experimental plots were selected each study year: plot A (PA), in which water was applied heterogeneously by using sprinklers with different nozzle combinations, and plot B (PB, used as the reference plot) in which the four sprinklers were maintained with the same nozzle combinations. Both experimental plots were divided into 25 subplots with the aim of studying the water distribution (measured as Christiansen uniformity coefficient (CU)), the impact on the actual evapotranspiration (ETa) and the yield obtained. Irrigation was scheduled using a daily simplified water balance method within the root area following the approach of the Food and Agriculture Organization. In the present study, sprinkler irrigation in PA resulted in lower CU (65–82% lower in 2002 and 59–79% lower in 2005) compared with PB (78–92% lower in 2002 and 79–93% lower in 2005). Between 30 May and 18 August 2002, the estimated crop water requirements in PA in the absence of water deficit was 22 mm over the accumulated value of ETc (491 v. 469 mm), while estimated crop water requirements under water deficit were 187 mm below ETc (282 v. 469 mm). In 2005, between 29 May and 25 August, ETa without water deficit was more similar to ETc (458 v. 444 mm) but Eta under water deficit was 242 mm. The greater uniformity of water distribution in PB was translated into a greater uniformity of yield distribution. A smaller range in yield was observed in PB when compared with PA. No statistically significant differences were observed between PA and PB in the crop quality parameters bulb moisture content, total soluble solids, pH and total acidity.


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