Numerical analysis of effect of the distributor and flow rate on internal flow in micro-pressure filters

Abstract

【Objective】 Micro-pressure filters are important components in micro-drip irrigation systems and their performance depends on many factors. In this paper, we study the impact of the distributor and water flow rate on water flow field within the filters. 【Method】 The study was based on numerical analysis. We used the software Fluent to simulate water flow in the filters under flow rates ranging from 5 to 17 m3/h, both with or without the water distributor. 【Result】 The standard k-ε turbulence model and the Volume of Fluid (VOF) model effectively simulated water flow fields within the filters. Without the water distributor, a dead water zone developed on either side of the front end of the filter screen, with its extent expanded as the flow rate increased. The maximum velocity was at the centre of the inlet connecting pipe, creating a velocity gradient shaped like an inverted cone within the filter screen. A high-pressure zone was developed at the bottom of the filter chamber, with its area decreasing with increasing flow rate. Adding a water distributor increased head loss, generated vortices, and reduced the dead water area. While the distribution of maximum water flow and pressure with and without the distributor was comparable, the distributor mitigated the influence of flow rate on velocity and pressure distributions in the filters. 【Conclusion】 The overall distribution patterns of velocity and pressure in the filters remained consistent across different flow rates. Adding a water distributor enhanced the flow field, improved filter screen use, and increased the efficiency of water inlet and outlet. These findings provide valuable insights for future research on optimizing water flow and improving the structural design of micro-pressure filters.

Keywords

• microdrip irrigation
• numerical simulation
• inlet flow
• water distributor
• flow field