Analysis of three-dimensional cake thickness structure characteristics in a screen filter for drip irrigation based on the CFD‒DEM coupling method

The three-dimensional filter cake structure is the focus of screen filter research. In order to explore the variation trend of filter cake thickness and thickness homogeneity under different inlet flow rates and different particle concentrations, the clogged mesh filters were studied by prototype and the CFD-DEM coupling experiment. The results showed that, as particle concentration increased, clogged filter cake thickness increased at first and dropped subsequently during the prototype experiment, which was determined by the number of particles per unit of time touching the screen and the particles of the force of interaction. Likewise, with an increasing inlet flow rate, the clogging cake thickness showed a slow decline and then tended to be stable during the prototype experiment, which was determined by the number of particles per unit of time touching the screen and the force of the flow field on the particles. The prototype experiment and simulation experiment showed the consistency of this trend. It was discovered that with the increase flow rate, the filter cake grade first increased then decreased after reaching a critical flow rate (160 m³ h⁻¹), and with the increase particle concentration the filter cake grade increased and then stabilised after reaching the saturation concentration (0.279 kg m⁻³). The best operating parameters were identified for filter functioning in actual irrigation based on the filter cake grade, to reduce clogging and simplifying future flushing.