Water–sediment separation experiment and numerical simulation in different gill-piece spacings of the gill-piece separation device

ABSTRACT Filters facilitate the removal of sticky sediments and prevent clogging of drip lines and emitters, thereby sustaining stable micro-irrigation system operation. In this study, physical model experiments were carried out at first. In the experiment, utilizing the shallow layer sediment theory and the principles of settling characteristics of viscous particles, the influence of different gill-piece spacing on water–sediment separation efficiency was analyzed and investigated under realistic working conditions. Furthermore, numerical simulations were performed using the mixture model and RNG k – ɛ models within the CFX software to supplement and verify the experimental results. Finally, the projection pursuit regression method is used for verification. Through the numerical simulations, the water–sediment two-phase flow field and volume concentration of sediment were studied, the influence of gill-pieces and different gill-piece spacing on the water–sediment separation efficiency of the gill-piece separation device (GPSD) was investigated, and the optimal gill-piece spacing of the GPSD was further explored. The results showed that GPSDs performed better than ordinary tubes in water–sediment separation. There was no significant difference in the water–sediment separation effect when the gill-piece spacing was less than 50mm. By taking both the water–sediment separation efficiency and economic benefits into consideration in practical engineering, the optimal gill-piece spacing was determined to be 50mm. Compared to GPSDs with gill-piece spacings of 80 and 110 mm, the water–sediment separation efficiency of the GPSD with a gill-piece spacing of 50 mm was 1.21–1.42 and 1.35–1.77 times higher, reaching a peak efficiency of 35.41%. The GPSD filter is small in size, simple in structure, and highly cost effective.