| In this paper,based on Fluent software,the finite element numerical simulation method was adopted to carry out the numerical simulation study on the 3-D flow field of the natural gas nozzle and fuel nozzle in the machining model.And the reliability of the simulation was verified with the experimental data under the requirement of technical indexes.Then,the same simulation scheme was adopted to carry out the numerical simulation study on the natural gas nozzle and fuel nozzle of the 3-D printing model.And the flow field distribution and performance parameters were analyzed under the relevant pressure conditions.The main research contents of this paper are as follows:(1)The performance parameters and flow field distribution of the natural gas nozzle in the machining model at 8 pressure conditions were numerically simulated.And the reliability of the numerical simulation was verified with experimental data under the requirement of technical indexes.The results showed that the maximum error of volume flow rate was 7.83%.(2)The inner flow field,the core flow field and the outer flow field of the fuel nozzle in the machining model were numerically simulated without auxiliary air.Then the performance parameters and distribution of atomized droplets of the fuel nozzle in the machining model at 7 pressure conditions were analyzed.And the reliability of the numerical simulation was verified with experimental data under the requirement of technical indexes.The results showed that the maximum errors of mass flow rate and spray angle were 9.83%and 4.63%,respectively.At the same time,the numerical simulation results of atomized particle size were verified by relevant references.(3)The atomization performance of the fuel nozzle in the machining model was numerically simulated with auxiliary air(14 kPa).Then the performance parameters and distribution of atomized droplets of the fuel nozzle in the machining model at 7 fuel pressure were analyzed.And the reliability of the numerical simulation was verified with experimental data under the requirement of technical indexes.The results showed that the error of volume flow rate was 9.62%.At the same time,the numerical simulation results of atomized particle size were verified by relevant references.4.The same simulation scheme was adopted to conduct a numerical simulation study on the natural gas nozzle and fuel nozzle of the 3-D printing model under the relevant pressure conditions.The results showed that the flow field distribution of the natural gas nozzle was good.At the same time,the maximum(minimum)of volume flow rate,mass flow rate and nonuniformity of the natural gas nozzle under the pressure conditions were 0.0355 m3·s-1(0.0252 m3·s-1),0.1341 kg·s-1(0.0203 kg·s-1),0.315(0.261),respectively.And the pressure at obstructive site of volume flow rate was 0.15 MPa;In the absence of auxiliary air,the distribution of atomized droplets in the fuel nozzle were conical and hollow.At the same time,the maximum(minimum)of mass flow rate,spray angle,atomized particle size and nonuniformity of the fuel nozzle under the pressure conditions were 0.1080 kg·s-1(0.0271 kg·s-1),1120(99°),266.79 μm(46.76 μm),0.647(0.487),respectively.And the value of SMD would be stable at about 46μm after being greater than 1.5 MPa;In different auxiliary air conditions,the distribution of atomized droplets in the fuel nozzle were conical and solid.At the same time,the maximum(minimum)of atomized particle size,spray angle and non-uniformity of the fuel nozzle under the pressure conditions were 35.93 μm(19.09 μm),1140(94°),0.830(0.719),respectively.And the value of SMD under different auxiliary air conditions(10,14,20 kPa)would be stable at about 30,28,25 pm,respectively.Based on the numerical simulation,this paper studied the flow field distribution and performance parameters of the natural gas nozzle and fuel nozzle in the 3-D printing model.And the research played a guiding role in the further optimization design of the subsequent 3D printing model. |
