evaluation of fluent software for simulation and costruction of a variable rate sprinkler for an autonomous irrigation system

water scarcity is today’s world biggest challenge which requires different countries to manage their water resources in the most efficient way. sprinkler irrigation increases water consumption efficiency due to more uniform distribution of water across the field. precision farming is based on the site-specific use of inputs according to soil characteristics and plant needs. one of the main inputs for agricultural production is water. thus, efficient use of water resources based on variable rate irrigation is considered to be a basic approach of precision irrigation. the main purpose of this study was to simulate and fabricate a variable flow sprinkler, applicable in solid set sprinkler irrigation system. the preliminary drawing of the proposed sprinkler, which equipped with a flow and pressure control plunger, was simulated using fluent software. the actual sprinkler was then fabricated and evaluated in a field. the performance of the sprinkler was evaluated at three pressure levels, three plunger positions (at the points of the least and biggest sprinkler’s cross section for water passage) and three diameters of outlet nozzle opening. results showed that the plunger had the capability of varying outlet flow and pressure in the sprinkler and trends in flow and pressure variation as affected by the plunger position was very complicated. the fluent model for conditions with fully open of the plunger and half opened was effectively efficient. however, as the plunger closed the water passage more than the half of cross section, the model did not show an acceptable efficiency.