Optimization Of The Structural Parameters Of The Bidirectional Flow Channel Emitter For Side Seam Drip Irrigation Belts

In this paper,a new type of bidirectional flow channel for side seam drip irrigation belt is developed.Using a combination of test experiments,simulation and optimisation calculations,the research is carried out to optimise the structural parameters of the bidirectional flow channel for side seam drip irrigation belts,which is of great significance to the development of agricultural water conservation.The main research results are as follows:(1)The design and processing of three different sets of side seam drip irrigation belt bidirectional flow channel samples with different structural parameters.The clear water test data shows that the hydraulic performance of the side seam drip irrigation belt bidirectional flow channel is better than the labyrinth flow channel;the muddy water test data shows that the side seam drip irrigation belt bidirectional flow channel also has better blocking resistance than the labyrinth flow channel.(2)By comparing the experimental results with the simulation results,a simulation method for the two-phase flow channel of the side seam drip irrigation belt is established.This method utilizes a grid size of 0.10mm,with the turbulence model as the standard k-ε and the two-phase flow model as the Euler-Lagrange model.In the two-phase flow model,the simulation results have the highest accuracy and the strongest correlation between particle passage rate and relative flow rate values when the equivalent particle size is 0.025mm,Correlation coefficient of 0.9926.(3)A simulation scheme of 40 groups of side seam bidirectional flow channels with different structural parameters is set up,and the simulation model established yields:the flow index of 40 groups of flow channels is 0.401-0.464,and the particle passage rate is 48.06%-98.1 8%,that is,the performance of side seam bidirectional flow channels with different structural parameters is different.Inside the flow channel,the pressure always shows a segmental decreasing change at the water retaining component.The sediment particles inside the flow channel constantly collide w ith the side wall and rotate at the bottom of the water retaining part,and finally deposit inside the flow channel,the higher the pressure the less the number of its rotation,and the stronger the anti-blocking performance of the flow channel.Inside the flow channel,the shorter the time of sediment particles traveling with the water,the stronger the anti-clogging performance of the emitter itself.(4)The response surfaces of the steady flow index and sediment particle throughput rate are developed for the two-way flow channel of the side seam drip irrigation belt.A multi-objective optimisation model for the structural parameters of the bi-directional flow channel of the side seam drip irrigation belt is developed with the objectives of minimising the steady flow index and maximising the sediment particle throughput rate,and a hierarchical multi-objective particle swarm algorithm is constructed to solve the mixed variables with continuous and discrete variables.The trade-off solution for the bidirectional flow channel parameters of the side seam drip irrigation belt under different situations is obtained.