New algorithm for hydraulic calculation in irrigation laterals

A new approach for solving lateral hydraulic problems in laminar or turbule nt flow is presented. The outflow is treated as a discrete variable event b y means of Taylor polynomials used to calculate flow rates along the latera l (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 late rals (with different pipeline diameter, slope, flow regime, or emitter spac ing) if a residual outflow Q(r) is used. The new approach can be used to ca lculate flow variation on laterals and submains in trickle or sprinkler irr igation systems without an excessive calculation effort. Results are compar able to those obtained in the literature.