Design of a micro-irrigation system based on the control volume method.

摘要

A microirrigation system design based on control volume method using the back step procedure is presented in this study. The proposed numerical method is simple and consists of delimiting an elementary volume of the lateral equipped with an emitter, called 'control volume' on which the conservation equations of the fluid hydrodynamics are applied. Control volume method is an iterative method to calculate velocity and pressure step by step throughout the microirrigation network based on an assumed pressure at the end of the line. A simple microcomputer program was used for the calculation and the convergence was very fast. When the average water requirement of plants was estimated, it is easy to choose the sum of the average emitter discharge as the total average flow rate of the network. The design consists of exploring an economical and efficient network to deliver uniformly the input flow rate for all emitters. This program permitted the design of a large complex network of thousands of emitters very quickly. Three subroutine programs calculate velocity and pressure at a lateral pipe and submain pipe. The control volume method has already been tested for lateral design, the results from which were validated by other methods as finite element method, so it permits to determine the optimal design for such microirrigation network..