Modeling of hydraulic characteristics through labyrinth emitter in drip irrigation using computational fluid dynamics

Mathematical model for hydraulic characteristics through labyrinth emitter in drip irrigation was established using computational fluid dynamics(CFD) in this paper. Computational fluid dynamics method was applied to calculate the relationship between the emitter discharge and pressure and the distributions of the pressure and velocity inside the emitter. The calculated results were compared with the test results of original emitters using amplified emitter model with dimension ratio of 10∶1. The results showed that the average error was less than 5% between the calculated values and tested values on the relationships of emitter discharge with pressure. The average pressure distribution error between calculated and measured value was less than 3%. The pressure change in the emitter was linear with the length of the flow path. The velocities near tooth cusp and bedrock in the labyrinth emitter were 1.6～2.8 m/s and 0.1～0.4 m/s, respectively. CFD method could be a powerful tool for emitter design and manufactures.