Analysis of local head losses in microirrigation lateral connectors based on machine learning approaches

[EN] The presence of emitters along the lateral, as well as of connectors along the manifold, causes additional local head losses other than friction losses. An accurate estimation of local losses is of crucial importance for a correct design of microirrigation systems. This paper presents a procedure to assess local head losses caused by 6 lateral start connectors of 32- and 40-mm nominal diameter each under actual hydraulic working conditions based on artificial neural networks (ANN) and gene expression programming (GEP) modelling approaches. Different input-output combinations and data partitions were assessed to analyse the hydraulic performance of the system and the optimum training strategy of the models, respectively. The range of the head losses in the manifold (hs(M)) is considerable lower than in the lateral (hs(L)). hs(M) increases with the protrusion ratio (s/S). hs(L) does not decrease for a decreasing s/S. There is a correlation between hs(L) and the Reynolds number in the lateral (Re-L). However, this correlation might also be dependent on the flow conditions in the manifold before the derivation. The value of the head loss component due to the protrusion might be influenced by the flow derivation. DN32 connectors and hs(M) present more accurate estimates. Crucial input parameters are flow velocity and protrusion ratio. The inclusion of friction head loss as input also improves the estimating accuracy of the models. The range of the indicators is considerably worse for DN40 than for DN32. The models trained with all patterns lead to more accurate estimations in connectors 7 to 12 than the models trained exclusively with DN40 patterns. On the other hand, including DN40 patterns in the training process did not involve any improvement for estimating the head losses of DN32 connectors. ANN were more accurate than GEP in DN32. In DN40 ANN were less accurate than GEP for hs(M), but they were more accurate than GEP for hs(L), while both presented a similar performance for hs(combined). Different equations were obtained using GEP to easily estimate the two components of the local loss. The equation that should be used in practice depends on the availability of inputs.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer NatureMartí Pérez, PC.; Shiri, J.; Roman Alorda, A.; Turegano Pastor, JV.; Royuela, A. (2023). Analysis of local head losses in microirrigation lateral connectors based on machine learning approaches. Irrigation Science. 41(6):783-801. https://doi.org/10.1007/s00271-023-00852-z783801416Al-Amoud AI (1995) Significance of energy losses due to emitter connections in trickle irrigation lines. 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Experimental and Numerical Analysis on Fluid-Structure Interaction Mechanism of Pressure-Compensating Emitter

학위논문(석사) -- 서울대학교대학원 : 농업생명과학대학 생태조경.지역시스템공학부(지역시스템공학전공), 2023. 2. 최원.지구 온난화로 인해 기후 변화가 촉진되고 수자원 안정성이 위협받고 있으며, 농업에서는 작물이 필요로 하는 물의 양이 증가할 것으로 예상된다. 점적 관개 시스템은 개별 작물 위치에 물을 직접 공급하여 작물의 품질 향상 및 생산량을 높이고 효율적인 물 소비가 가능하게 하는 관개 방법이다. 점적 관개는 수원지에서 멀어지면서 관 내부의 압력이 저하되고 유출 유량이 불균일한 문제가 있으나, 점적 관에 부착된 압력보상 이미터는 불균일한 압력에도 균일한 유량을 유지하여 이러한 문제를 해결할 수 있다. 미래 정밀 관개를 위해서는 공급 압력 범위에서 목표 유량을 나타내는 압력보상 이미터 설계가 필수적이며, 설계 최적화에 앞서 원리 도출과 신뢰성 있는 성능 예측이 필수적이다. 그러나, 압력보상 이미터는 작은 크기로 인해 내부 탄성막과 용수의 상호작용 기작을 실험적으로 관찰하는 것이 어려우며, 내부 탄성막과 용수가 변형되기 때문에 전산유체역학 해석에 한계가 있다. 본 연구에서는 이러한 한계를 해결하기 위해 상사 법칙을 적용한 압력보상 이미터의 확대 모형 실험과 양방향 유체-구조 연계해석 모델을 설계하였으며, 이를 통해 압력보상 이미터의 유체와 구조 상호작용 기작을 분석하였다. 확대 모형 실험 결과에서 압력보상 이미터 성능에는 변형된 탄성막에 의한 유출구 시작부 단면적 감소가 주요한 것으로 분석되었다. 또한, 압력보상 이미터 형상에 따라 유량의 급격한 감소를 유도하는 탄성막 진동 현상이 발생하여, 이에 대한 방지 설계가 필요한 것으로 판단되었다. 압력보상 이미터의 설계 변경에 따른 성능 영향을 관찰하기 위해, 대상 압력보상 이미터 (Case 1), 미로 유로 형상 (Case 2)과 탄성막 강성 (Case 3)이 변경 설계된 모형 실험과 양방향 유체-구조 연계해석 결과를 비교하였다. 이를 통해, 미로 유로 형상의 변화는 최대 유출 유량의 변경에 주요한 영향을 미치며, 탄성막 강성의 변화는 압력보상 구간을 이동시키고 넓이를 변경시키는데 주요한 것으로 분석되었다. 양방향 유체-구조 연계해석 모델을 이용하여 최대 유출 유량이 나타나는 압력 구간까지 실험과 10 % 이내 오차로 예측 가능하였다. 수치해석 결과, 압력보상 구간 성능에는 챔버 영역의 압력 저하와 난류 운동 에너지 손실이 주요하였으며, 내부 미로 유로, 탄성막 강성과 챔버 치수가 주요 설계인자로 판단되었다. 원형 크기로 환산된 Case 1·2·3 의 압력보상 구간은 각각 1.54 – 3.84, 1.28 – 3.65와 1.86 – 4.67 bar, 최대 유량은 각각 3.62, 2.90과 4.13 L/hr로 상이하게 나타났으며, 이를 고려하여 압력보상 구간이 대상지 지형과 가압 조건에 따른 지점별 수두를 포함하면서 최대 유량이 작물 최적 유량을 만족하는 압력보상 이미터 설계가 가능할 것으로 판단된다. 추후, 본 연구의 분석 결과를 바탕으로 압력보상 이미터의 성능 예측 모델을 개선하고, 농경지 조건에 적합한 최적의 점적 관개 시스템을 설계할 수 있을 것으로 기대된다.It is expected that global climate change induces an instability of water resource and increases water requirement of crop. Drip irrigation system is an irrigation method that directly supplies water to individual crop, so that improves not only quality and yield of crop, but also efficiency of water consumption. Flow rate to individual crop generally increases according to inlet pressure of water at each orifice, so that amount of irrigation water to each crop is irregular. PC (Pressure-Compensating) emitter attached to drip irrigation pipe can regulate the flow rate uniformly. For precision irrigation, it is essential to design PC emitter that discharges target flow rate within supplied inlet pressure range. Prior to design optimization, the derivation of mechanism and reliable performance prediction must be preceded. However, it is difficult to observe deformation of elastic membrane pressurized by water, due to the small size of PC emitter. Because domain of fluid and structure are simultaneously deformed, computational fluid dynamics cannot analyze the PC emitter. In this study, an enlarged model experiment and two-way FSI (Fluid-Structure Interaction) analysis model were designed to analyze the interaction mechanism between the water and elastic membrane. By matching the flow rate and deformation according to inlet pressure of experiment, the flow rate of PC emitter was uniform at the pressure range that deformed elastic membrane reduced the cross-sectional area of outlet. The catastrophe phenomenon (i.e. vibration of elastic membrane) occured at the specific PC emitter. Because the vibration of elastic membrane destabilized the flow rate, it is necessary to design the PC emitter preventing vibration. The model of PC emitter (Case 1) was compared with the PC emitter that geometry of labyrinth channel (Case 2) and stiffness of elastic membrane (Case 3) were changed. Through the results of experiment, the geometry of labyrinth channel mainly affected the maximum flow rate, and the stiffness of elastic membrane mainly affected pressure range of PC. The two-way FSI analysis model could analyze up to the inlet pressure of maximum flow rate, but cannot predict decrease section. The prediction error was within 10 % compared with the experiment, especially accurate at PC section. By analyzing the simulation results of pressure decrease and turbulence kinetic energy at fluid domain, the chamber domain were main factor for uniform flow rate at the PC section. Along with the geometry of labyrinth channel and stiffness of elastic membrane, the chamber geometry was the main design parameter. The PC section of original model of case 1,2, 3 were 1.54 – 3.84, 1.28 – 3.65 and 1.86 – 4.67 bar, respectively. The maximum flow rates were 3.62, 2.90 and 4.13 L/hr, respectively. The yield and quility of crop were different according to the flow rate of drip irrigation pipe. Therefore, the PC emitter has to be designed that PC section includes the pressure range of target site and the maximum flow rate meet the optimal flow rate of target crop. Based on the results of this study, it is expected that the development of performance prediction model and optimization design of drip irrigation system will be possible.제 1 장 서론 1 1.1 연구 배경 및 필요성 1 1.2 연구 목적 5 제 2 장 연구사 7 2.1 이미터의 실험적 연구 7 2.2 이미터의 수치해석 연구 9 2.3 상사 법칙에 의한 모형 실험 12 제 3 장 재료 및 방법 13 3.1 연구 대상 13 3.1.1 대상 압력보상 이미터 13 3.1.2 설계 인자별 압력보상 이미터 모델링 14 3.2 확대 모형 실험 17 3.2.1 수리학 상사성 검토 17 3.2.2 탄성막 상사성 검토 20 3.2.3 실험 설정 23 3.3 양방향 유체-구조 연계해석 모델 27 3.3.1 양방향 유체-구조 연계해석 27 3.3.2 전산유체역학 설정 30 3.3.3 구조해석 설정 36 3.3.4 해석 솔버 및 요소망 설정 37 제 4 장 결과 및 고찰 39 4.1 유체-구조 상호작용 기작의 실험적 분석 39 4.1.1 압력보상 이미터 확대 모형의 배율 결정 39 4.1.2 확대 모형 실험 결과 분석 41 4.1.3 압력보상 이미터 설계 인자 영향 분석 48 4.2 유체-구조 상호작용 기작의 수치적 분석 51 4.2.1 양방향 유체-구조 연계해석 예측 정확성 검증 51 4.2.2 유체-구조 영역의 국부적 거동 분석 55 4.3 압력보상 이미터 최적 설계 인자 고찰 65 제 5 장 요약 및 결론 67 참고문헌 69 Abstract 78석

Advances in Hydraulics and Hydroinformatics Volume 2

This Special Issue reports on recent research trends in hydraulics, hydrodynamics, and hydroinformatics, and their novel applications in practical engineering. The Issue covers a wide range of topics, including open channel flows, sediment transport dynamics, two-phase flows, flow-induced vibration and water quality. The collected papers provide insight into new developments in physical, mathematical, and numerical modelling of important problems in hydraulics and hydroinformatics, and include demonstrations of the application of such models in water resources engineering

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.The two-layer model of Shuttlerworth and Wallace (SW) was evaluated to estimate actual evapotranspiration (ETa) above a drip-irrigated Merlot vineyard, located in the Talca Valley, Region del Maule, Chile (35° 25' LS; 71° 32' LW ; 136m above the sea level). An automatic weather system was installed in the center of the vineyard to measure climatic variables (air temperature, relative humidity, and wind speed) and energy balance components (solar radiation, net radiation, latent heat flux, sensible heat flux, and soil heat flux) during November and December 2006. Values of ETa estimated by the SW model were tested with latent heat flux measurements obtained from an eddy-covariance system on a 30 minute time interval. Results indicated that SW model was able to predict ETa with a root mean square error (RMSE) of 0.44 mm d-1 and mean absolute error (MAE) of 0.36 mm d-1. Furthermore, SW model predicted latent heat flux with RMSE and MAE of 32 W m-2 and 19W m-1, respectively

USCID Fourth international conference on irrigation and drainage

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Integrated regional water management -- Change of irrigation water quantity according to farm mechanization and land consolidation in Korea -- Local stakeholders participation for small scale water resources management in Bangladesh -- Water user participation in Egypt -- The man swimming against the stream knows the strength of it -- Roles and issues of Water Users' Associations for Sustainable Irrigation and Drainage in the Kyrgyz Republic and Uzbekistan in Central Asia -- Chartered Water User Associations of Afghanistan -- Updated procedures for calculating state-wide consumptive use in Idaho -- Measuring and estimating open water evaporation in Elephant Butte Reservoir in New Mexico -- Evapotranspiration of deficit irrigated sorghum and winter wheat -- Evaluation of a two-layer model to estimate actual evapotranspiration for vineyards -- Estimating pecan water use through remote sensing in Lower Rio Grande -- Estimating crop water use from remotely sensed NDVI, crop models, and reference ET -- Alfalfa production using saline drainage water -- Performance evaluation of subsurface drainage system under unsteady state flow conditions in coastal saline soils of Andhrapradesh, India -- Management strategies for the reuse of wastewater in Jordan -- Providing recycled water for crop irrigation and other uses in Gilroy, California -- Oakdale Irrigation District Water Resources Plan -- Use of information technology to support integrated water resources management implementation -- Decision-support systems for efficient irrigation in the Middle Rio Grande -- Salt management -- Ghazi Barotha Project on Indus River in Pakistan -- Field tests of OSIRI -- Water requirements, irrigation evaluation and efficiency in Tenerife's crops (Canary Islands, Spain) -- Using wireless technology to reduce water use in rice production -- Variability of crop coefficients in space and time -- Assessing the implementation of integrated water management approach in closed basins -- New strategies of donors in the irrigation sector of Africa -- Holistic perspective for investments in agricultural drainage in Egypt -- Mapping system and services for canal operation techniques -- An open channel network modernization with automated structures -- Canal control alternatives in the irrigation district 'Sector BXII del Bajo Guadalquivir,' Spain -- Hydrodynamic behavior of a canal network under simultaneous supply and demand based operations -- Simulation on the effect of microtopography spatial variability on basin irrigation performance -- Drip irrigation as a sustainable practice under saline shallow ground water conditions -- Water retention, compaction and bean yield in different soil managements under a center pivot system -- Precision mechanical move irrigation for smallholding farmers -- Wild flood to graded border irrigation for water and energy conservation in the Klamath basin -- A method describing precise water application intensity under a CPIS from a limited number of measurements -- An irrigation sustainability assessment framework for reporting across the environmental-economic-social spectrum -- Planning for future irrigation landscapes -- One size does not fit all -- Water information networks -- Improving water use efficiency -- Irrigation system modernization in the Middle Rio Grande Valley -- Relationship of operation stability and automatic operation control methods of open canal -- Responsive strategies of agricultural water sector in Taiwan -- Effect of network water distribution schedule and different on-farm water management practices on sugarbeet water use efficiency -- Variable Frequency Drive (VFD) considerations for irrigation -- Accuracy of radar water level measurements -- Transition submergence and hysteresis effects in three-foot Cutthroat flumes -- Practical irrigation flow measurement and control -- Linear anionic PAM as a canal water seepage reducing technology -- In-situ non-destructive monitoring of water flow in damaged agricultural pipeline by AE -- Reoptimizing global irrigation systems to restore floodplain ecosystems and human livelihoods -- Water management technologies for sustainable agriculture in Kenya -- Impacts of changing rice irrigation practices on the shallow aquifer of Nasunogahara basin, Japan -- Drought protection from an in-lieu groundwater banking program -- Development of agricultural drought evaluation system in Korea -- Bean yield and root development in different soil managements under a center pivot system -- Can frost damage impact water demand for crop production in the future? -- Real time water delivery management and planning in irrigation and drainage networks -- Growth response of palm trees to the frequency of irrigation by bubblers in Khuzestan, Iran -- Application of Backpropagation Neural Network to estimate evapotranspiration for ChiaNan irrigated area, Taiwan -- Increasing water and fertilizer use efficiency through rain gun sprinkler irrigation in sugar cane agriculture

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.A In order to promote irrigation sustainability through reporting by irrigation water managers around Australia, we have developed an adaptive framework and methodology for improved triple-bottom-line reporting. The Irrigation Sustainability Assessment Framework (ISAF) was developed to provide a comprehensive framework for irrigation sustainability assessment and integrated triple-bottom-line reporting, and is structured to promote voluntary application of this framework across the irrigation industry, with monitoring, assessment and feedback into future planning, in a continual learning process. Used in this manner the framework serves not only as a "reporting tool", but also as a "planning tool" for introducing innovative technology and as a "processes implementation tool" for enhanced adoption of new scientific research findings across the irrigation industry. The ISAF was applied in case studies to selected rural irrigation sector organisations, with modifications to meet their specific interests and future planning

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Since 3000 BC, rice has been the main crop in the Korean Peninsula, and where currently most of the available irrigation water is used to grow paddy rice. Methods for calculating the quantity of irrigation water required developed in the 1990's were compared to quantities measured in the field. The largest difference between calculated and measured quantities occurred in April and May. Based on field data we obtained in the middle part of the Korean Peninsula, significant changes have occurred in rice management, which has changed the amount of irrigation water required. Rice is now transplanted earlier, and duration of the transplanting phase on the regional scale is shorter through mechanization and consolidation of land holdings. These changes need to be taken into account when calculating the quantity of water needed for irrigation

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Experiences establishing Water User Associations (WUAs) in Egypt have been carried out for the past 15 years, with increasingly promising results. Most of these activities have been pilot projects aiming to demonstrate the benefits and sustainability of WUAs. They were consequently implemented through a centralized and resource-intensive process and focused on limited numbers of associations. Since 2003, the Ministry of Water Resources and Irrigation (MWRI) has adopted as policy the large-scale development of Branch Canal WUAs. With support from USAID, about 600 branch canal WUAs (BCWUAs) have since been established, covering 15% of Egypt's irrigated area and involving half a million farmers and residents. In order to achieve this impressive outcome, a different approach has been developed and implemented, emphasizing the direct involvement of MWRI field staff and a partnership between water users and MWRI managers. This paper also argues that the conventional approach of forming WUAs by focusing on water users, and empowering them to take over the O&M responsibilities of irrigation systems, is not adapted to the Egyptian context

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Salt management is a critical component of irrigated agriculture in arid regions. Successful crop production cannot be sustained without maintaining an acceptable level of salinity in the root zone. This requires drainage and a location to dispose drainage water, particularly, the salts it contains, which degrade the quality of receiving water bodies. Despite the need to generate drainage water to sustain productivity, many irrigation schemes have been designed and constructed with insufficient attention to drainage, to appropriate re-use or disposal of saline drainage water, and to salt disposal in general. To control the negative effects of drainage water disposal, state and federal agencies in several countries now are placing regulations on the discharge of saline drainage water into rivers. As a result, many farmers have implemented irrigation and crop management practices that reduce drainage volumes. Farmers and technical specialists also are examining water treatment schemes to remove salt or dispose of saline drainage water in evaporation basins or in underlying groundwater. We propose that the responsibility for salt management be combined with the irrigation rights of farmers. This approach will focus farmers' attention on salt management and motivate water delivery agencies and farmers to seek efficient methods for reducing the amount of salt needing disposal and to determine methods of disposing salt in ways that are environmentally acceptable