Structural Design And Experimental Study On Hydraulic Performance Of Emitters With Labyrinth Channel

Drip irrigation is one of the most effective methods in water-saving irrigation. As the key parts in drip irrigation system, emitters will affect the uniformity and reliability of the irrigation system. Using the parameterized design method to develop new products will realized the production of serialized drip irrigation products, shorten the product development cycle and cost.Considering that there is no quantitative guideline in labyrinth emitters design, the characteristic parameters of the rectangular channel unit are extracted. Four key characteristic parameters are obtained: the channel width, the unit length, the unit height and the sum of the channel units. Integral emitters are fabricated by the Laser Rapid Prototyping technology without mold. The experiment and numerical simulation are carried out with orthogonal design method, both of them are used to get the hydraulic performance data, and the relationship between the key structural parameters of rectangular labyrinth and hydraulic performance is studied. The result obtained show that the unit width is the most important factor affecting the flow index, and the flow rate is seriously influenced by the number of channel unit. The emitter's regression model between parameters and hydrodynamic behavior is established.Aiming at the clogging problem of emitters, Fluent(based on Computational Fluid Dynamics)is used to simulate the single-phase and two-phase flow field inside the rectangular channel of the labyrinth drip tape. The analytical results show that the labyrinth channel and inlet structure design of the emitter are unreasonable, which caused the clogging of the labyrinth channel. In addition, a lot of vortexes with low flow speed existed inside labyrinth channel based on the CFD simulation, which may result in the clogging. Then the presumption is proved by the particle's tracks in two-phase flow analysis. Based on these analyses, we optimized the whole structure of the emitter's inlet, unit and outlet, and the velocity distribution and particle's movement inside the optimized labyrinth channel are studied. The results indicate that the flow pattern is improved inside the optimized labyrinthchannel, the vortexes are reduced, and the anti-clogging performance of the labyrinth drip tape is enhanced.