Caracterização hidráulica de linhas laterais, em sistemas localizados, que utilizam microtubos de tamanho variado como emissores.

Abstract

This study consisted in the development of a model adapted for computer, for dimensioning and hydraulic characterization of lateral pipes, in localized systems, which use microtubes of varying size as emitters. The criterion for dimensioning the model is based on the compensation of pressure losses on the side, with the variation of the length of the emitters along these, distributed over sections whose pressure variation, between extremes, does not exceed 20%. 0 model it was adjusted to a maximum load variation on the side, in order to condition: the flow regime at the emitter; emitter length and desired flow rate per emitter. A computer program in BASIC language, in the GWBASIC version, it was used to implement the necessary calculations are sizing, and to issue reports in the form of tables that can be used for sizing sides with emitters of varying size. The results of tests conducted without a Laboratory, to hydraulically characterize the emitter, evaluate and validate the calculations carried out through the model, allowed the following conclusions: the microtubes that were used as emitters in this study, are mostly classified as good or average in relation to manufacturing / installation uniformity according to classification of ABREU (1983). The flow regime in the emitters with lengths between 6 and 20 cm and for hydraulic loads between 3 and 12 mca, and unstable and partially turbulent, reducing the sensitivity of these emitters to temperature variations and clogging, which affect the uniformity of water distribution . To evaluate and validate the model, three sides dimensioned through it were chosen at random, and the water distribution uniformities results are: 89, 27 and 94, 24%; 83.20 and 89, 58%; 81.62 and 89.39%, calculated respectively by the SOIL CONSERVATION methods SERVICE - USDA (1978) and CHRISTIANSEN (1942).