scholarly journals A field study on hydraulic performance of drip irrigation system for optimization of operating pressure

2017 ◽  
Vol 9 (4) ◽  
pp. 2261-2263
Author(s):  
Mairaj Hussain ◽  
Sudhiranjan Prasad Gupta

Drip irrigation technology will undoubtedly plays an important role in the future of the agriculture. A field experiment was conducted to evaluate the performance of drip system with five operating pressure viz. I1 (0.4 kg/ cm2), I2 (0.6 kg/cm2), I3 (0.8 kg/cm2), I4 (1.0 kg/cm2), I5 (1.2 kg/cm2). It was observed that the average discharge of drippers was 1.08 lph, 1.24 lph, 1.50 lph, 1.62 lph and 1.74 lph and emission uniformity was 80.55%, 84.89%, 86.30%, 88.88% and 90.80 in each treatment respectively and coefficient of variation was observed 0.12, 0.13, 0.12, 0.11, and 0.09. Flow component was found 0.450 and the value of k was 0.572 while R2 was observed 0.986.Based on the result it can be concluded that the operation of drip irrigation system at 1.2 kg/cm2 pressure head, gives the maximum efficiency in respect of discharge, emission uniformity and coefficient of variation.

2021 ◽  
Vol 904 (1) ◽  
pp. 012013
Author(s):  
B A AL-Dulaimi ◽  
Sh M AL-Mehmdy

Abstract A field experiment was conducted in Jazeerah Al-Ramadi/Al-Hamidiyah research station (latitude33^o 27^’ 〖 11.9 〗 ^(՚՚)N, longitude 43^o 23^’ ^(՚՚) E (duration 2020. This study was conducted to investigate the effect of pipe types and emitters discharge on performance criteria of surface drip irrigation system. Therefore, a two factorial experiment was set as randomized complete block design with three replications. The first factor included the type of pipes and emitters, namely Turbo, GR and T-Tape. While the second factor involved the emitters discharge which consist of two levels i.e., 4 (D4) and 8 (D8) L.h-1. The irrigation system was initially evaluated in the field before planting by testing three operating pressures (50, 100 and 150 Kpa) to determine the actual discharge of the emitters closed to their design discharge (4 and 8 L.h-1) for each emitter to calculate the manufacturing coefficient of variation (CV), distribution uniformity and the discharge variation ratio at each operating pressure. Results showed that the best discharge (Closed to design discharge of 4 L.h-1) was obtained at the 50 Kpa operating pressure which gave 3.99,3.90 and 3.81 L.h-1 when using the T-Tape pipe and GR and Turbo emitter compare when the discharge of 8L.h-1 has been used which gave 7.96, 7.84 and 7.59 L.h-1 when the former pipe and emitters were used. The best coefficient of variation was observed when the T-Tape pipe and GR and Turbo emitter were used with discharge of 4 L.h-1 up to 0.1300, 0.2200 and 0.2600 compare to 0.1300, 0.2700 and 0.3500 when the same former pipe and emitters were used with discharge of 8L. h-1. Similarly, the best distribution uniformity was obtained when the T-Tape pipe and GR and Turbo emitter has been used with discharge of 4 L.h-1 which gave 94.68, 91.74 and 90%. Likewise, the most acceptable variety discharge ratio was observed when the same prior pipe and emitters were used with discharge of 4 L.h-1 by giving 7.23, 11.90 and 12.19 %.


Irriga ◽  
2019 ◽  
Vol 1 (1) ◽  
pp. 86-93
Author(s):  
Verônica Gaspar Martins Leite de Melo ◽  
Leonardo Leite de Melo ◽  
José Antônio Frizzone ◽  
Antônio Pires de Camargo ◽  
Patricia Angélica Alves Marques

PERDA DE CARGA EM FITAS GOTEJADORAS COM EMISSORES MOLDADOS     VERÔNICA GASPAR MARTINS LEITE DE MELO1; LEONARDO LEITE DE MELO2; JOSÉ ANTÔNIO FRIZZONE3; antônio pires de camargo4 E patricia algélica alves marques5   1 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 2 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 3 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 4 Faculdade de Engenharia Agrícola – UNICAMP, Av. Cândido Rondon, 501, Cidade Universitária, CEP 13083 - 875, Campinas, SP, e-mail: [email protected] 5 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected]     1 RESUMO   Embora as fitas gotejadoras sejam de baixo custo, é importante que esse material seja avaliado hidraulicamente para prover informações técnicas. O objetivo deste trabalho foi analisar a perda contínua de carga e o fator de atrito em uma fita gotejadora com emissor moldado em seu interior. O experimento foi conduzido no laboratório de irrigação da ESALQ/USP. Utilizou-se a fita gotejadora Rain-Tape® fabricada pela Rain Bird®, espessura de parede de 225 µm e emissores tipo labirinto, espaçados de 0,30 m, vazão nominal de 1 L h-1 e pressão de serviço de 55 kPa. A equação de perda de carga para regime de escoamento turbulento liso em função da vazão e da carga de pressão na entrada da fita apresenta boa habilidade para estimar a perda de carga em fitas gotejadoras com emissores moldados, sendo que 95% das estimativas apresentaram erro relativo de até 6,71%. A equação de Darcy-Weisbach pode ser utilizada para o cálculo da perda de carga desde que o diâmetro seja substituído por uma função da pressão de entrada. Para o cálculo da perda de carga, utilizando a equação de Darcy-Weisbach, o fator de atrito calculado pela equação de Blasius deve considerar um coeficiente a = 0,3408.   Palavras-chave: irrigação por gotejamento, perda de carga por atrito, fator de atrito     MELO, V. G. M. L. de; MELO, L. M. de; FRIZZONE, J. A.; CAMARGO, A. P. de; MARQUES, P. A. A. HEAD LOSS IN DRIP TAPES WITH MOLDED EMITTERS     2 ABSTRACT   Although drip tapes are low-cost equipment, proper hydraulic evaluation is important to provide information required for irrigation system design. The aim of this study was to analyze the friction head loss and the friction factor in drip tapes with molded emitters, that are employed in drip irrigation systems. Experiments evaluated the drip tape model Rain-Tape®, manufactured by Rain Bird, 225-µm wall thickness, labyrinth-type emitters, 0.30-m emitters spacing, 1 L h-1 nominal discharge and operating pressure of 55 kPa. The following conclusions were obtained: (a) the equation of head loss for smooth turbulent flow as a function of flow rate and pressure head at the pipe inlet provided good predictions of head loss in drip tapes with molded emitters, since 95% of predictions presented relative errors less than 6.71%; (b) the Darcy-Weisbach equation may be used for calculating head loss, but the pipe diameter must be replaced by a function considering the lateral inlet pressure; (c) for calculating head loss of the Rain-Tape using the Darcy-Weisbach equation, the friction factor obtained by the Blasius equation should use the coefficient a = 0.3408.   Keywords: drip irrigation, frictional head loss, friction coefficient


Author(s):  
Parth J. Kapupara ◽  
Hina M. Bhatu ◽  
Jay Gohel

Background: Drip irrigation system is one of the best water application methods that have been used in the world among the other irrigation methods because of its upright and high uniformity and high-water use efficiency. Hydraulic performance evaluation is widely accepted for the evaluation of overall uniformity of a drip irrigation system. Methods: In an experimental study carried out at School of Engineering, RK University, Rajkot; hydraulic performance evaluation parameters viz., Pressure discharge relationship, Christiansen’s uniformity coefficient (CU), manufacturing coefficient of variation (CVm) and emission uniformity (EU) of non-pressure compensating emitters were calculated for 2 lph inline and 2 lph, 4 lph, 8 lph online emitter at various operating pressure of 0.8, 0.9, 1.0, 1.1 and 1.2 kg/cm2 as per American Society of Agricultural and Biological Engineers (ASAE) standards. Result: The study concluded that rated discharge of the emitter can be obtained at the operating pressure of 1.0 kg/cm2. Pressure discharge relationship revealed that discharge of the emitter upsurges as pressure rises. CU and EU were more than 95% for all the cases and they were maximum at 1.0 kg/cm2. CVm was less than 0.0200 for all the cases and it was minimum at 1.0 kg/cm2. Study concludes that all the parameter viz., CU, EU and CVm were excellent and very good categories for all emitters as per American Society of Agricultural and Biological Engineers (ASAE) standards.


Author(s):  
Eddy Herman Sharu

Irrigation is the most important component in ensuring that crops can produce optimal yields. The use of drip irrigation can help farmers in providing water to crops in the amount required by the crop. Drip irrigation usually uses an uncompensated dripper and also a pressure compensated dripper. The use of an uncompensated dripper requires precise pressure to ensure a uniform flow for each dripper while the use of a pressure compensated dripper will also provide a uniform flow when operating pressure was used within the range specified by the dripper manufacturer. The purpose of this study is to evaluate the hydraulic performance of the drip irrigation system using low pressure compared to the minimum pressure recommended by dripper manufacturers. The pressure operation recommended by the manufacturer is 1.5-4 bars. This study uses pressures as low as 1 bar (low pressure), 2 bars, and 2.5 bars (recommended by manufacture) to operate this irrigation system. The volumetric approach was used to calculate each emitter's flow rate. Coefficient uniformity (CU), emission uniformity (EU), coefficient of variation (CV), and emitter flow variation (EFV) were the hydraulic parameters evaluated. The results show that CU, CV, and EU are in excellent classification, and the value for CU and the EU is more than 95 percent efficiency. The CV value is below 0.03 which is a very good classification. Meanwhile, emitter flow variation is 10% when operating at 2.5 bars and 2.0 bars and is considered the desirable classification. On the other hand, the emitter flow variation was reported at 6% for the 1 bar operating pressure and the classification was also recorded in the desirable classification. The results conclude that the use of low operating pressure compared to the minimum operating pressure proposed by the manufacturer can also operate in excellent condition according to the hydraulic parameters evaluated.


2021 ◽  
Vol 910 (1) ◽  
pp. 012015
Author(s):  
Hussein Razzaq Nayyef

Abstract An experiment was carried out in Al-Rifai District - Dhi Qar Governorate, to study the effect of the distance between drippers and their discharge on friction losses, coefficient of variation, and emission consistency of the drip irrigation system. Spiral drippers with a design discharge of 4 and 8 L.hr"1. While the emitters were installed at distances of 20, 40, 60 (cm). The actual discharge of the droplets was measured and the friction losses, emission consistency coefficient, and discharge variance ratio were calculated. The results showed that the distance between the emitters 60 cm gave the lowest percentage of friction losses, which amounted to 0.165, 0.204 (m) for drippers with design drainage of 4, 8 L.hr-1. The best values of the emission consistency coefficient and the variance ratio in the emitters discharge were 95.44 and 28.41% when using the 8L.hr-1 and the distance between the emitters is 60 cm, respectively.


2021 ◽  
Vol 0 (6) ◽  
pp. 4-8
Author(s):  
Daler Domullodzhanov

The article describes the results of field and laboratory experiments on the study of the technology of drip irrigation of potatoes via using the semi-stationary low-pressure small-capacity drip irrigation system (LDIS) developed by us. Reinforced aluminium micro-tubes ensure uniform watering. Depending on the annual precipitation sufficiency, the potatoes irrigation requirements 1700…3400 m3/ha, the number of irrigations varied from 10 to 20 times, and the yield was between 54…58,2 tons per ha.


Author(s):  
Jerzy Jeznach

Some maintenance problems of the drip irrigation in Poland Drip irrigation system will play in the future a significant role in fulfilling the requirements of intensive, energysaving agricultural production. Total area under microirrigation in Poland can be now estimated as about 10 000 hectares. Drip irrigation is applied mainly in orchards, vegetable farms and greenhouses. The investigations on drip irrigation have shown a high infl uence of the agricultural conditions on the operation and reliability and productivity effects of the irrigation system. Paper present the investigation of the operation of drip irrigation systems in various regions of Poland. The analysis is based on the results of the manufacture coefficient of variation Cv, emitter exponent n, uniformity coefficient and detailed observation of the work time, breaks, failures and any other damages to the system.


Author(s):  
S. Vanitha ◽  
S. Senthilvel

Micro irrigation system should ensure relatively same amount of water to each plant along the total length of lateral line. In general, the drip irrigation systems are low to medium operating pressure head systems with a pressure requirement in range of 0.5 kg/cm2 to 2.5 kg/cm2 depending on the area irrigated and field layout geometry. However, since these systems are pressure irrigation systems which require appropriate operating pressure heads to deliver the required rates of flow, the inevitable frictional head losses are to be compensated for maintaining uniformity in water application. Hence, the hydraulic gradient compensation needs to be achieved by some viable mechanism so that the inequality in pressure heads and discharges can be eliminated or minimized. The crop production will have its maximum yield and water use efficiency only one the water distribution uniformities at its the highest. Hydraulic gradient compensation assumes a vital role in compensating the operating pressure heads as well as the emitter discharges. The hydraulic gradient compensated drip lateral layout registered high order of water distribution uniformity in the range of 97.8% and irrigation usage efficiency in the range of 17.98 kg/ha/mm to 20.69 kg/ha/mm for 2 lph emitter arrangements.


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