Effect of fluid flow diversion and venturi size on drip irrigation fertilizer feeding system

Abstract

Modeling and simulation studies of drip irrigation systems have been carried out to improve the fertilizer suction rate for the existing water flow rate of 20,000 litres per hour to the agricultural field. Venturi design (33 mm, 40 mm and 50 mm venturi inlet diameters) and water entry/exit modifications (90° inlet/outlet, 45° inlet & 90° outlet and 45° inlet/outlet) have been carried out in the models and the incompressible fluid flow is simulated in OpenFOAM 5.0 using the simpleFoam solver and realizable K-epsilon (k-ε) turbulence model. Mesh refinement level of (4, 5) was used which is considered as medium grid size. The results are validated using real time experimental setup in the agricultural field. In all the selected conditions, the throat velocity increases linearly with increase in pressure drop and with some variations in the flow distribution. The simulated results obtained for various design conditions using OpenFOAM software satisfies the real time experimental outputs and the 45° entry/exit angle coupled with 33 mm inlet diameter venturi yields the maximum suction rate at the lowest pressure difference.