Effects of shell material characteristics on hydraulic performance of bubbled-root emitter
CHEN Rui1,ZHU Delan1,2*,WU Shoujun1,ZHANG Lin2,3
1. College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China; 2. Institute of Water Saving Agriculture in Arid Areas of China, Northwest A&F University, Yangling, Shaanxi 712100, China; 3. Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China
Abstract:The hydraulic performance of emitters with different shell materials should be investigated. The bubbled-root emitters made by 5 kinds of shell materials(ABS, HDPE, HDPE+20%EVA, LDPE+20%EVA, 40%HDPE+40%LDPE+10%LLDPE+10%EVA)were selected. The effects of shell material characteristics, such as shrinkage, modulus and tensile deformation on hydraulic performance were tested. The results showed that the effects of shell materials physical properties on emitter out-flow were significant. The larger the molding shrinkage of the shell material is, the closer the inner diameter of emitter shell is. Thus, the labyrinth channel fitted more closely to the shell, which led to a decrease of emitter flow rate. The shell material with better rigidity had stronger ability to resist the external deformation. Consequently, emitter flow rate was more stable as the pressure head increased. The emitter shell with better nature rebound resilience had lower manufacturing variation under the same manufacturing process. Therefore, in order to obtain a bubbled-root emitter with better hydraulic performance, the selection of emitter shell material should balance the rigidity and nature rebound resilien-ce. In this study, the most appropriate material for bubbled-root emitter shell is 40%HDPE+40%LDPE+10%LLDPE+10%EVA.
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