NEW ALGORITHM FOR HYDRAULIC CALCULATION IN IRRIGATION LATERALS

A new approach for solving lateral hydraulic problems in laminar or turbulent flow is presented. The outflow is treated as a discrete variable event by means of Taylor polynomials used to calculate flow rates along the lateral (minimal outflow included). The friction head losses are calculated using the Darcy-Weisbach equation with a nonconstant logarithmic friction factor f. This algorithm allows hydraulic computation for a set of connected laterals (with different pipeline diameter, slope, flow regime, or emitter spacing) if a residual outflow [Q.sub.r] is used. The new approach can be used to calculate flow variation on laterals and submains in trickle or sprinkler irrigation systems without an excessive calculation effort. Results are comparable to those obtained in the literature.