Optimal structure selection of emitter flow path in drip irrigation system with inferior water resources : Selecao ideal da estrutura do caminho do fluxo do emissor em sistema de irrigacao por gotejamento com recursos hidricos inferiores

The fundamental solution to the problem of emitter clogging is to explore the optimal structure design of emitter and improve its anti-clogging ability. The research objective was to select the optimal structural form of the emitter flow path in drip irrigation systems using inferior water sources, which can provide theoretical support for improving the anti-clogging ability of the emitter itself and designing new emitter products. The selection of the flow path structure of the emitter has not been conducted on the basis of determining the appropriate simulation model with the condition of complex water quality. Therefore, the appropriate internal fluid movement model of the emitter was determined, the hydraulic performance and anti-clogging performance of the five nationally and internationally representative flow path structures were comprehensively evaluated, and finally the optimal structure of the emitter flow path was determined. The research results indicated that RNG k - [epsilon] model was the most suitable to simulate the flow field in the emitter by comprehensive analysis of the gap between simulated values and the measured values, the calculation accuracy and computational efficiency. The fractal flow path was relatively optimal for hydraulic performance and for anti-clogging performance. This study can provide theoretical support for improving the anti-clogging ability of the emitter itself and the design of the new emitter product. Key words: hydraulic performance, anti-clogging performance, numerical simulation A solucao fundamental para o problema do entupimento do emissor e explorar o projeto ideal da estrutura do emissor e melhorar sua capacidade anti-entupimento. O objetivo da pesquisa foi selecionar a forma estrutural ideal do caminho de fluxo do emissor em sistemas de irrigacao por gotejamento utilizando fontes de agua de qualidade inferior, proporcionando suporte teorico para melhorar a capacidade anti-obstrucao do proprio emissor e para o projeto de novos produtos de emissores. A selecao da estrutura do caminho do fluxo do emissor nao tem sido conduzida com base na determinacao do modelo de simulacao apropriado com a condicao complexa de qualidade da agua. Para tanto, determinou-se o modelo de movimento interno do fluido adequado do emissor, e avaliou-se de forma abrangente o desempenho hidraulico e o desempenho anti-entupimento das cinco estruturas representativas da trajetoria de fluxo no pais e no exterior, e finalmente determino