Numerical Simulation Of Hydraulic Characteristics And Energy Dissipation And Pressure Stabilization Of Embedded Infusion And Irrigation Device During Water Filling

In order to find out the cause of serious soil erosion caused by embedded irrigation device,I study the transient hydraulic characteristics of embedded irrigation device during water filling process based on the combination of numerical simulation and theoretical analysis,and carries out numerical simulation of energy dissipation and voltage stabilization optimization by installing energy dissipation orifice plates in this paper.The results are expected to provide guidance for optimizing the structure of embedded irrigation device,reducing soil erosion caused by outflow in fruit tree root area,and have important significance for further popularization of embedded irrigation device in the field of water-saving irrigation in arid areas.In this paper,the Realizable k-epsilon model and VOF method were used to numerically simulate the water-gas two-phase flow characteristics during the water filling process of the embedded irrigation device.The results show that the water flow in the outlet channel of the embedded irrigation device is transient flow,and the peak value greater than the inlet pressure appears repeatedly during the water filling process,which causes the instantaneous flow peak value of the outlet hole greater than the outlet flow under the constant flow state,and causes orifice jet,causing serious erosion of local soil around the outlet hole.When the inlet pressure P0=13.8k Pa?30k Pa,the peak pressure in the outlet pipe is 3.27?4.7 times of the inlet pressure,and the maximum instantaneous flow rate is 1.66?2.09 times of the outlet flow rate under constant flow condition.In this paper,an energy dissipation orifice plate is added to the embedded injector to reduce the instantaneous peak pressure during water filling.The results show that the orifice plate installed at the bottom of the vertical inlet pipe(L₁/L₂=0)has the most significant energy dissipation and voltage stabilization effect,while the orifice plate installed at the beginning of the vertical inlet pipe(L₁/L₂=1)has no obvious or even ineffective effect on reducing the instantaneous pressure peak value of the outflow channel.The orifice plate water flow area accounts for 50%of the total orifice plate area(A₁/A₂=0.5)has the most significant energy dissipation and voltage stabilization effect,A₁/A₂=0.6 and 0.75When the number of orifice holes n=1 and 2,the instantaneous pressure peak during water filling can be effectively reduced,and the pressure fluctuation range can be reduced.The energy dissipation and voltage stabilization effect of n=2 is better than that of n=1,and the energy dissipation and voltage stabilization effect of n=3 on the outlet channel is not obvious.The simulation results show that Scheme 6(L₁/L₂=0,A₁/A₂=0.5,n=2)is the best scheme for energy dissipation and voltage stabilization among the seven improved schemes designed in this paper.