Optimization of the design of labyrinth emitter for agriculture irrigation using computational fluid dynamic analysis

Abstract

Fluid dynamic simulations are used to improve the efficiency of flat drippers commonly used in agriculture to optimize the irrigation system.. These emitters have a particular configuration of the labyrinth channel appropriately shaped to ensure high turbulence and dissipation of the hydraulic load. The analysis was carried out investigating the labyrinth geometry by means of computational fluid dynamics technique. Several simulations were performed in order to investigate on the relationship between the flow rate, in liters per hour, and the pipe pressure. Seven different dripper models were analyzed to change the size of the dissipation channel and therefore the flow rate. The emitter discharge was investigated for three inlet pressure values 50, 100 and 150 kPa. This way it was possible to calculate the law that rules the pressure-flow curve. Basically, the geometry was modified thus to optimize the exponent of the emitter. The value of the exponent is closely linked to the conformation of the channel and is standardized by the International Organization for Standardization (ISO) 9261:2004. Furthermore, the relation between the cross sectional area of the labyrinth channel and the flow rate was investigated.