SPRINKMOD - pressure and discharge simulation model for pressurized irrigation systems. 1. Model development and description

A computer model was developed to simulate pressure and flow rate distribut ion along pipes and laterals of pressurized irrigation systems in operation . The software runs in a Windows environment and is capable of simulating i rrigation systems having multiple pump stations combined in series and/or i n parallel, booster pump stations, parallel pipes and looping pipes. Hand-m ove, wheel line and center pivot laterals with pressure regulators, one or two drop pipes per outlet and booster pump can be simulated. Leakage can be included in the main pipe network or along the laterals. Lateral inlet pre ssure can be set to an upper limit to simulate valve closure. Practically a ny type of nozzle and pump can be simulated since cubic spline functions ar e used to interpolate values from head-flow rate sets of data. To accomplis h these capabilities, algorithms were developed and adapted to convert late rals into a set of head-flow rate data so that a simplified algorithm could be adapted to solve the entire pipe network. A user-friendly interface was designed to allow data for pumps, nozzle and pressure regulators to be int eractively entered, edited and analyzed prior to the simulation run. The la yout of the irrigation system can be drawn on screen using the mouse. Data can be independently entered and edited for each irrigation system componen t already drawn in the screen, at any time and in any order. Data for the e ntire irrigation system are verified at many levels before the simulation i s run, to make the model less susceptible to crash. The model proved to be a practical tool for upgrading and designing pressurized irrigation systems .