Rapid structural design of drip irrigation emitters based on RP technology

Purpose The paper aims to summarize the design theory for labyrinth channels of water saving emitters. Design/methodology/approach On the basis of extracting the structural parameters of labyrinth channels in water saving emitters, the hydraulic performance experiments on the integral emitters fabricated with higher resolution rapid prototyping technology are performed. Then, using multivariable linear regression, formulas of pressure versus flow rate and regression plots for different emitters are induced. Findings The formulas of flow rate versus structural parameters are summarized based on the trapezoid-type channel unit, and verified through experiments. The relationships between flow rate, pressure and structural parameters of channels are established. Research limitations/implications The effect of emitter fabrication error on the flow rate is analyzed, which provides a basis for parameterized structural design and accuracy control in the fabrication of future emitters. Practical implications The Q-H-n relationship equations are used to design emitters which have flow-rate errors under both high- and low-water pressure of less than 4 percent. So the Q-H-n relationship equation of the emitter is well proven and accurate which can guide the design for the structure of emitters with trapezoid labyrinth channels. Originality/value In this paper, a new stereolithography system has been used to fabricate accurately a drip irrigation emitter with a complex microstructure, which cannot be obtained with conventional RP or other manufacturing processes. Compared to other manufacturing process, this new technique has higher manufacturing accuracy and can reduce the manufacturing cost and time. Furthermore, a design theory for labyrinth channels of water saving emitters is established.