scholarly journals Impact of the Intermittency Movement of Center Pivots on Irrigation Uniformity

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1167
Author(s):  
Abdelmoneim Z. Mohamed ◽  
R. Troy Peters ◽  
Abid Sarwar ◽  
Behnaz Molaei ◽  
Don McMoran
Keyword(s):  
Cycle Time ◽  
High Speed ◽  
Travel Speed ◽  
Movement Direction ◽  
Irrigation Uniformity ◽  
Center Pivot ◽  
Go Model ◽  
Distribution Uniformity ◽  
Coefficient Of Uniformity ◽  
Move Distance

A computer model was developed to simulate the varying depths of water applied to the ground due to the intermittent movements of a typical center pivot. The stop–go model inputs include the sprinkler application depth, the sprinkler pattern, that pattern’s wetted radius, the center pivot’s % timer setting, the move cycle time, and the end tower maximum travel speed. The model outputs were the depth of application in the pivot’s movement direction, the distribution uniformity (DU), and the coefficient of uniformity (CU). The results revealed that the pivot circular application uniformity is mostly a function of the move distance as a percent of the sprinklers’ wetted radius. This, in turn, is a function of the percent timer setting, the cycle time, and the end tower travel speed. Due to this, the high-speed center pivots had corresponding lower application uniformities compared to low-speed machines, and sprinklers with larger wetted radii resulted in better uniformity. Shortening the cycle time also resulted in higher uniformity coefficients. Based on these results, it is recommended that the run time be set based on the pivot end-tower’s travel speed and sprinkler wetted radius, such that the end tower move distance is equivalent to the sprinkler wetted radius. This will reduce wear to the tower motors due to the on–off cycling, especially for slow travel settings and for sprinklers with larger wetted radii. The ponding depths at different percent of the move distance, for the potential runoff, were estimated, which were set to be equivalent to the wetted radius.

Effect of Combination Factors of Operating Pressure, Nozzle Diameter and Riser Height on Sprinkler Irrigation Uniformity

2014 ◽  
Vol 695 ◽  
pp. 380-383 ◽  
Author(s):  
Manal Osman ◽  
Suhaimi B. Hassan ◽  
Khamaruzaman B. Wan Yusof
Keyword(s):  
Irrigation System ◽  
Sprinkler Irrigation ◽  
Nozzle Diameter ◽  
Operating Pressure ◽  
Irrigation Uniformity ◽  
Distribution Uniformity ◽  
Coefficient Of Uniformity ◽  
Riser Height ◽  
Design Factors ◽  
Pressure Nozzle

The irrigation uniformity of sprinkler irrigation system depends on many design factors such as nozzle type, nozzle diameter, operating pressure and riser height. An experimental study was performed to investigate the effect of combination factors of operating pressure, nozzle diameter and riser height on sprinkler irrigation uniformity. Different operating pressures, nozzle diameters and riser heights have been used. The irrigation uniformity coefficients such as coefficient of uniformity (CU) and distribution uniformity of low quarter (DUlq) have been studied. This study concluded that, the irrigation uniformity of sprinkler irrigation system was more affected by the combination of operating pressure, nozzle diameter and riser height.

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

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1916 ◽  
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.

Spray irrigation on dairy pastures - efficient or not?

2006 ◽  
pp. 177-181
Author(s):  
S.M. Thomas ◽  
D. Bloomer ◽  
R.J. Martin ◽  
A. Horrocks
Keyword(s):  
Irrigation System ◽  
Groundwater Resources ◽  
Dairy Farmers ◽  
Large Variability ◽  
Irrigation Application ◽  
Irrigation Uniformity ◽  
Survey Results ◽  
Spray Irrigation ◽  
Use Efficiency ◽  
Distribution Uniformity

Applying water efficiently is increasingly important for dairy farmers and other users of surface and groundwater resources to maintain sustainable production. However, irrigation is rarely monitored. We used a questionnaire survey and measurements of five spray irrigation systems working in normal farm conditions to make observations on how efficiently irrigation is being managed. Survey results from 93 dairy farmers showed that, although the farmers believe they know how much water is being applied during irrigation, only 60% make measurements, and about 18% measure irrigation uniformity. Catch-can measurement of irrigation application depth for the different spray systems indicated large variability in application depths during irrigation, and field distribution uniformity ranged greatly between the different systems, decreasing in the order of centre pivots >travelling irrigators> K-line. Changes in irrigation system settings were sometimes made without considering application depths or uniformity. If our five case studies are typical, they may explain the large range of seasonal irrigation amounts recorded in the survey. We recommend that farmers monitor irrigation application depths and uniformity to help manage irrigation water efficiently and to help them estimate the value of irrigation to their enterprise. Keywords: distribution uniformity, water use efficiency, catch cans

scholarly journals Evaluation of the coefficient of uniformity and non-uniformity of irrigation for wide-range irrigators in various field conditions

2018 ◽  
Vol 64 (No. 2) ◽  
pp. 55-62
Author(s):  
Jobbágy Ján ◽  
Krištof Koloman
Keyword(s):  
Linear Model ◽  
Evaluation Methods ◽  
Field Conditions ◽  
Work Quality ◽  
Specific Field ◽  
Irrigation Uniformity ◽  
Wide Range ◽  
Coefficient Of Uniformity ◽  
Input Variables

The aim of this paper is to address an issue of work quality of irrigation machines with eight parameters that were selected and defined as input variables. The objective of the study was to determine possibilities of different evaluation methods for a wide range of irrigation machines and their versatility. All input conditions that could affect the results were recorded and analysed. The results were statistically analysed by a linear model (ANOVA). The results confirm that there are no statistically significant differences in used evaluation methods (p > 0.05) when the effect of locality was not considered. When the effect of locality was considered, statistically significant differences were observed (p < 0.05). When considering the coefficient of non-uniformity, statistically significant differences were not observed, however in case of considering different irrigation machines, statistically significant differences were observed. The obtained results indicate that the evaluation of irrigation uniformity is possible to carry out with other methods; however, the specific field conditions are not interchangeable as a parameter.  

Design and Test of a Double-Curved Guiding Groove for a High-Speed Precision Seed-Metering Device

2020 ◽  
Vol 63 (5) ◽  
pp. 1349-1360
Author(s):  
Pan Xue ◽  
Yujun Hao ◽  
Wan Jiao ◽  
Jie Ren ◽  
Feifei Yang ◽  
...  
Keyword(s):  
Inclination Angle ◽  
High Speed ◽  
Element Model ◽  
Discrete Element ◽  
Travel Speed ◽  
Curved Surface ◽  
Discrete Element Model ◽  
Release Point ◽  
Seed Spacing ◽  
Seed Metering Device

HighlightsThe instability of the seed release point in a seed-metering device is proved theoretically.A double-curved guiding groove at the seed-release point improves the seed-metering uniformity.A discrete element model was used to examine effects of the design parameters on the metering performance.The critical parameters for the double-curved guiding groove design were determined.Abstract. The instability of the seed release point in a seed-metering device is one of the main causes of the non-uniformity of seed spacing. To improve the seed spacing uniformity, a double-curved guiding groove (DGG) was designed based on the prerelease adaptive principle. The DGG was used at the seed release point of an existing high-speed precision soybean seed-metering device with a double-setting plate. The results showed that the prerelease curved surface of the DGG was capable of guiding seeds to be released at the same seed release point at all times, and the adaptive curved surface of the DGG prevented any changes in seed velocity caused by friction or collisions between seeds and the meter, thereby improving the seed spacing uniformity significantly. A discrete element model was developed and validated with laboratory tests. Through simulations using the model, the primary and secondary factors of the DGG impacting the qualified rate of seed metering (QRM) and the coefficient of variation of the seed spacing uniformity (CVU) were identified and were, in descending order, the spacing of prerelease (SPR), the starting position of prerelease (SPP), the inclination angle of the seed outlet (ASO), and the inclination angle of the receiving cup (ABR). Regression equations of the QRM and CVU with the two main impacting factors were then established. For a planter travel speed of 10 km h-1, the optimal SPR was 10 mm, and the optimal SPP was 40°, where the QRM was 100% and the CVU was 16.61%. When compared to seed metering without the DGG, the CVU was reduced by 2.55%, showing that the DGG significantly improved the uniformity of seed spacing. Keywords: Double-curved guiding groove, Discrete element method, Seed-metering device, Travel speed, Uniformity.

HIGH-SPEED INDUSTRIAL REAL-TIME NETWORK OF CYBERPHYSICAL SYSTEMS

2019 ◽  
pp. 46-52
Author(s):  
A. A. Zelensky
Keyword(s):  
Real Time ◽  
Cycle Time ◽  
High Speed ◽  
High Efficiency ◽  
Industrial Robot ◽  
Field Tests ◽  
Industrial Robots ◽  
Third Party ◽  
Industrial Equipment ◽  
Industrial Automation

The construction of a high-speed industrial real-time network based on FPGA (Field-Programmable Gate Array) for the control of machines and industrial robots is considered. A brief comparative analysis of the performance of the implemented Ethernet-based Protocol with industrial protocols of other leading manufacturers is made. The aim of the research and development of its own industrial automation Protocol was to reduce the dependence on third-party real-time protocols based on Ethernet for controlling robots, machines and technological equipment. In the course of the study, the requirements for the network of the motion control system of industrial equipment were analyzed. In order to synchronize different network nodes and provide short exchange cycle time, an industrial managed switch was developed, as well as a specialized hardware controller for processing Ethernet packets for end devices, presented as a IP-core. A key feature of the developed industrial network is that the data transmission in it is completely determined, and the exchange cycle time for each of the network devices can be configured individually. High efficiency and performance of implemented network devices became possible due to the use of hardware solutions based on FPGAs. All solutions described in the article as part of a modular digital system have been successfully tested in the control of machines and industrial robot. The results of field tests show that the use of FPGAs and soft processors with specialized peripheral IP-blocks can significantly reduce the tact of managing industrial equipment through the use of hardware computing structures, which indicates the promise of the proposed approach for solving industrial automation tasks.

Capacitor Discharge Weld Modelling Using Ultra High Speed Photography

1993 ◽  
Vol 314 ◽  
Author(s):  
R. D. Wilson ◽  
J. A. Hawk ◽  
J. H. Devletian
Keyword(s):  
High Speed ◽  
Welding Process ◽  
Travel Speed ◽  
Analytical Models ◽  
High Speed Photography ◽  
Welding Time ◽  
Capacitor Discharge ◽  
Ultra High Speed ◽  
High Cooling Rates ◽  
Weld Area

AbstractCapacitor discharge welding (CDW) is a rapid solidification joining process where high cooling rates (106 K/s) are obtained as a result of the large weld surface area to small weld volume. The objective of this study, directed by the U.S. Bureau of Mines and the Oregon Graduate Institute of Science and Technology, was to use ultra-high speed photography to quantify transient arc behavior during the CDW cycle. The simple cylindrical geometries of the CD welds have been used to formulate analytical models which are compared to the high speed photographs of the welding process. The high speed photographs were analyzed with respect to welding time and process weld variables and compared to predicted values from the analytical model. The detailed photographic analyses revealed that material is continuously ejected as a plasma from the weld area due to induced magnetic forces, rather than having the liquid metal squeezed out of the weld upon contact. It was found that welding time was controlled by tip length and drop height. Results from high speed photographs found the arc travel speed around tube welds to be 109m/s. Finally, the high speed photographs revealed that the velocity of arc propagation during ignition was fast enough to allow the CDW process to be modelled as onedimensional heat flow.

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