Water And Particle Simulation And Energy Consumption Analysis Based On CFD-DEM Labyrinth Runner Emitter

In this paper,the labyrinth flow irrigation emitter is taken as the research object.The intermittent short-cycle hydrophobic test is also adopted.This paper studies the effects to the clogging of the labyrinth flow emitter exert by the irrigation inlet pressure,irrigation frequency time,irrigation interval days.LS-CWM laser particle size analyzer is adopted to measure the gradation changes before and after the discharge of the emitter in order to determine the sensitive particle size that can easily cause the emitter to clog.In the meanwhile,this paper applies the CFD-DEM coupling computational method to establish numerical model for the blocking mechanism of labyrinth flow channel.It is to make a theoretical analyze for the passing rate of particles of different sizes in the labyrinth flow channel under different pressures,the hydraulic performance of the emitter and the intrinsic energy consumption of different parameters.Through orthogonal test,the particle movement and deposition are to be studied.Moreover,the orthogonal test is to find the optimal combination of factor levels in the ideal state to provide a theoretical basis for the designing of labyrinth channel.The conclusions of this paper are as follows:Firstly,when the inlet pressures are the same,angles have significant effects on the total passing rate of the particles in the emitter.When the particle size is between 0.0625-0.05 mm,the angle has the most significant effect on its passing rate.Particles of other parameters may have effects but not significant effects.When the inlet pressures are different,as the pressure increases,the passing rate is positively correlated with the pressure.The orthogonal analysis is also carried out which shows that the factor angle has a significant effect on the flow index,and the remaining factors have no significant effect.Secondly,with the increase of pressure,the total consumption of particles,namely the Et changes clearly.When the pressure increases by 50 KPa,the average of the total consumption of the particles will increase by 78.56%.When the pressures are the same,with the increase of particle sizes,Et will increase in different level.When the pressures are the same,the total energy consumption of small particles is small with little collisions and the passing rate is high.Similarly,the large particles consume a large amount of energy with more collisions,and the passing rate is low.Thirdly,it is because that there is no energy exchange between the inner system of the emitter and the outside world,the head loss in the channel is provided by the pressure drop.The pressure of the emitter gradually decreases from the inlet along the flow and has a linear downward trend.When the pressure increases,the resistance coefficient and the local resistance coefficient will be increased obviously.The angle has a significant effect on the flow index and the local resistance coefficient.Lastly,under different pressure,the relative flow rate of emitters of different in different flow paths gradually decreases with the increase of the testing days.On the whole,it is declining.The effect of irrigation time on emitter clogging has reached a significant level.Then it comes to the irrigation pressure and the intervals between irrigation.under different pressure in different inlets,all the gradation change from instable to stable.With the increase of pressure,the volume ratio of large particles becomes larger.