Economic Design and Analysis of Multi-Diameter Sprinkler Irrigation Laterals

This paper addresses the hydraulic and economic design of multi-diameter sprinkler irrigation lateral pipes with constant slope and similar, equally spaced sprinklers. The friction losses are estimated using the Darcy-Weisbach formula, taking into account the turbulent flow regions on the Moody diagram. Individual sprinklers are considered in estimating discharge and pressure along the lateral pipe. Other factors accounted for include: changes in velocity at sprinkler heads losses in sprinkler risers and pipe fittings and loss is due to the sudden contraction of pipes. A computer program is presented for the design of laterals having smaller downstream diameters such that hydraulic design criteria are met. This program provides economical designs for sprinkler irrigation laterals. Two numerical examples are presented in which some practical cases are analyzed