Caracterização Hidráulica De Um Tubo Gotejador

Frizzone, José Antônio; Vieira, Angelita Teresinha; Paz, Vital Pedro da Silva; Botrel, Tarlei Arriel

doi:10.1590/1807-1929/agriambi.v2n3p278-283

Cited by 27 publications

(22 citation statements)

References 1 publication

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“…This result was also observed by Lima et al (2014), who studied the manufacturing and flow variation coefficients in self-compensating emitter using saline water. Whereas the flow cross sections are usually of small diameter, manufacture must be accurate, uniform and constantly monitored because small variations in pressure can cause large differences in flow rate (FRIZZONE et al, 1998).…”

Section: Resultsmentioning

confidence: 99%

Characterization of the hydraulic performance of self-compensating emitters with water of different salt concentrations

et al. 2016

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The aim of the present study was to evaluate hydraulic characteristics such as manufacturing and flow variation coefficient, characteristic equation of self-compensating emitters and the variation between nominal flow and that obtained by the emitter equation using waters of different salt concentrations. The research was conducted in the greenhouse of the Academic Unit of the Agricultural Engineering, Federal University of Campina Grande-PB. Treatments consisted of five salinity levels in the irrigation water (ECwi) (0.6; 1.5; 2.5; 3.5 and 4.5 dS m -1 at 25 ° C) and four working pressures (60, 100, 140, and 160 kPa), with three replicates. The flow variations of emitters were considered small over time, being within recommendation of ± 7% of the nominal flow with "x" exponent values between 0.02 and 0.09, as recommended by the manufacturer, which was classified as self-compensating. The manufacturing and flow variation coefficients were considered excellent in all evaluations and the operating time did not influence the hydraulic performance of emitters. At pressure of 60 kPa and electric conductivity of 0.6 dS m -1 , flow rates near values provided by the manufacturer and more economically viable to the farmer were obtained. ResumoObjetivou-se, com o presente estudo, avaliar as características hidráulicas, como coeficiente de variação de fabricação e vazão, equação característica do emissor autocompensante e a variação entre a vazão nominal e a obtida pela equação do emissor utilizando águas de diferentes concentrações salinas. A pesquisa foi conduzida na casa de vegetação da Unidade Acadêmica de Engenharia Agrícola, Universidade Federal de Campina Grande-PB. Os tratamentos foram compostos por cinco níveis de salinidade da água de irrigação (CEai) (0,6; 1,5; 2,5; 3,5 e 4,5 dS m -1 a 25 °C) e quatro pressões de serviço (60, 100, 140, e 160 kPa), com três repetições. As variações de vazão dos emissores foram consideradas pequenas ao longo do tempo, de modo que estavam dentro da recomendação de ± 7% da vazão nominal, com valores de expoente "x" entre 0,02 e 0,09, segundo recomendação do fabricante, que os classificou como autocompensantes . Os Coeficientes de variação de fabricação e de vazão foram considerados excelentes em todas as avaliações e o tempo de funcionamento não influenciou no desempenho hidráulico dos emissores. Na pressão de 60 kPa associada à condutividade elétrica da água de 0,6 dS m -1 , obtiveram-se vazões dos emissores mais próximas da declarada pelo fabricante e a mais economicamente viáveis ao produtor. Palavras-chave: Vazão nominal. Coeficiente de variação de fabricação. Salinidade. Equação característica.

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Section: Resultsmentioning

confidence: 99%

Characterization of the hydraulic performance of self-compensating emitters with water of different salt concentrations

et al. 2016

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“…Segundo Frizzone et al (1998) A relação entre a pressão no segmento de tubo de derivação (Pst) calculada com a observada, pode ser visualizada na Figura 4. As Pst observadas foram de 2,3; 2,9; 6,0 e 8,0 kPa e diferiram das Pst determinadas nos cálculos, que foram de 5,3; 7,3; 17,3 e 28,4 kPa, apresentando valores inferiores aos estimados para as pressões de alimentação utilizadas nos ensaios, constatando-se que estava ocorrendo perda localizada de carga, isto ocorre quando o fluido sofre alguma perturbação brusca em seu escoamento, por algum elemento nele inserido, causando turbulência local (Cardoso & Frizzone, 2007;Zitterell et al, 2009;Gomes et al, 2010).…”

Section: Avaliação Hidráulica Do Sistemaunclassified

Modelagem para o dimensionamento de um sistema de microirrigação utilizando microtubos ramificados

Alves

Pinto

Salvador

et al. 2012

Rev. bras. eng. agríc. ambient.

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R ESU M OEste trabalho foi realizado com o objetivo de se modelar e avaliar o comportamento hidráulico de microtubos ramificados, com base na relação entre vazão e comprimento dos microtubos para uma pressão de entrada, operando sob regime laminar. Dois modelos matemáticos foram estudados, em que um considerou a perda localizada de carga no dimensionamento dos microtubos ramificados e o outro a desconsiderou. O experimento para validação dos modelos foi conduzido no Laboratório de Hidráulica da Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ-USP), Piracicaba, SP, medindo-se a vazão dos emissores para as pressões de 14,7; 18,6; 39,2 e 58,9 kPa. A configuração do sistema de irrigação consistiu de uma linha lateral com diâmetro nominal (DN) de 10,0 mm, na qual foram inseridos microtubos conectores com DN de 0,8 mm conectados a um segmento de tubo de derivação e acoplados seis microtubos emissores com DN de 0,7 mm. Verificou-se que, dentre os modelos matemáticos, aquele que considerou a perda localizada de carga apresentou maior exatidão pois teve elevado, um bom índice de Willmott e baixo erro quadrático médio.Palavras-chave: emissores, tecnologia de irrigação, perda de carga, modelo matemático, baixo custo Modeling for the design of a micro-irrigation system using branched microtubes A B ST R A C T This study was carried out with the aim to develop a mathematical model and to evaluate the hydraulic behavior of branched microtubes, based on the relationship between discharge and microtube length for a specific inlet pressure, operating under laminar flow conditions. Two mathematical models were studied in which one considered the local head losses in irrigation system design and the another did not consider. The experiment for model validation was carried out at the Laboratory of Hydraulics, School of Agriculture "Luiz de Queiroz" (ESALQ/USP), Piracicaba-SP, where emitter discharges was verified under the pressures of 14.7; 18.6; 39.2 and 58.9 kPa. The irrigation system configuration consisted of a lateral line with nominal diameter (DN) of 10.0 mm, in which are inserted microtube connectors with 0.8 mm DN. These connectors are connected to a derivation tube segment, where six emitter microtubes with 0.7 mm DN were attached. It was verified that the model which considered the local head losses showed better accuracy than other mathematical models, as this model showed a good Willmott index and a low mean quadratic error.

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“…It is known that the process capability index is the response and the process is operating within specification limits provided; it is necessary that is in statistical control and that the values of flow and Christiansen Uniformity coefficients (CUC) have close to normal distribution and thus observe the quality of irrigation (GONÇALEZ & WERNER, 2009). FRIZZONE et al (1998, claim that as the flow variation has normal distribution, it is possible to use statistical concepts to make quantitative analysis.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Self Compensating Emitters Irrigating With Saline Water: Part Ii: Process Capability Index

et al. 2016

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ABSTRACT:The use of tools such as process capability index for irrigation aims to observe how this irrigation is adequate in terms of quality. The aim of the study was analyzing the Christiansen uniformity coefficient and the flow of a drip irrigation system with self-compensating emitters under water different salt concentrations, using the process capability index. The research was conducted in a greenhouse at the Federal University of Campina Grande (UFCG). The experimental design was a randomized block in a factorial 5 x 2 with three replications, the factors consisted of five levels of irrigation water salinity (CEw) (0.6, 1.5, 2.5, 3.5 and 4.5 dS m -1 at 25°C) and two running times (0 and 350 hours of operation). The Christiansen uniformity coefficient (CUC) for new and used emitters was greater than 90%, in different salt concentrations studied. The flow of emitters is maintained within the statistical quality control, since management and maintenance operations are made after 350 hours of operation. The potential process capability index for the Christiansen uniformity coefficient was higher than recommended for new and used emitters, being the process within the required specifications.

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Caracterização Hidráulica De Um Tubo Gotejador

Cited by 27 publications

References 1 publication

Characterization of the hydraulic performance of self-compensating emitters with water of different salt concentrations

Characterization of the hydraulic performance of self-compensating emitters with water of different salt concentrations

Modelagem para o dimensionamento de um sistema de microirrigação utilizando microtubos ramificados

Evaluation of Self Compensating Emitters Irrigating With Saline Water: Part Ii: Process Capability Index

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