Perda localizada de carga em conectores utilizados em microirrigação

Abstract

Local head losses in the connectors used in microirrigationLocal losses are often neglected in design of irrigation systems affecting the uniformity of water application. Some accessories have no simple and efficient equations to estimate these losses. The main objective of this work was to develop an equation to estimate the local head loss in the lateral passage connectors. 11 models of connectors in 12 different diameters of pipes were tested forming 15 groups of pipe/connector. The connectors were characterized by its internal diameters and dimensions. The local head loss was determined by subtracting the head loss on the connector and pipe from the head loss on the pipe. The parameters affecting the local head loss were defined as dimensionless terms using Buckingham's theorem. A mathematical model was developed and presented a determination coefficient of 93.31%. Elements such as inner diameter of the connector and pipe length, connector, water flow velocity, Reynolds number and Froude number influenced the local head loss in the connectors. The model was compared with the observed data and presented a performance classified as excellent and can be used in calculating of the local head loss in the lateral passage connectors.

Comparação entre o Método Trecho-a-Trecho e o Método de Múltiplas Saídas no dimensionamento de uma linha lateral de um sistema de irrigação por aspersão

“…As equações para estimar a perda de carga foram determinadas ou deduzidas teoricamente para um regime de escoamento específico (Zitterell, 2011). O regime de escoamento pode ser classificado laminar se o Número de Reynolds for até 2.000 e turbulento quando acima de 4.000, valores entre 2.000 e 4.000 são considerados regime de transição, porém em sistemas de irrigação pressurizados geralmente os valores são muito acima de 4.000.…”