Flow characteristics in energy dissipation units of labyrinth path in the drip irrigation emitters with DPIV technology

The energy dissipation mechanism and anti-clogging properties of drip irrigation emitters are closely related to flow characteristics of the fluid in its flow paths, and flow field tests using modern flow visual technologies were carried out by a large number of designers. The Digital Particle ImageVelocimetry (DPIV) system was built for un-disturbed flow tests in the labyrinth path. In this article, the flow field was measured in the flow path section, the structural unit and the local region near sawtooth. Under the pressure level of 10 Kpa, 50 Kpa, 100 Kpa and 150 Kpa, the flows in the two labyrinth paths were in the turbulence state, with flow stagnation regions and whirlpool regions in the structure of the labyrinth path sections. The flow stagnation regions should be eliminated as much as possible. But the vortex should be fully developed, which could increase the self-cleaning capacity and the anti-clogging capacity of the emitter. With respect to the anti-clogging performance and the energy loss efficiency of the emitter, the M-type flow path is better than the K-type flow path.