Experimental And Simulation Research On The Process Of Internal-mixing Twin-fluid Atomization

The atomization process of the internal-mixing twin-fluid atomizer breaks the liquid jet into smaller droplets by means of the disturbing action of the gas,so as to obtain a better atomization effect.It is widely used in various power mechanical devices.Therefore,the internal mixing type is studied.The liquid fragmentation process of the air atomizing nozzle is of great significance.In this paper,the spray characteristics of internal-mixing air atomization nozzles are tested and studied by three methods: experiment,theoretical research and numerical simulation.The crack model was analyzed and optimized and calculated and verified,and the numerical simulation of the secondary atomization process of internal mixing air atomization was carried out.The test process uses water and air as media,and when the liquid flow rate is 10L/h,15L/h,20L/h,the nozzle flow characteristics,spray fragmentation shape,spray cone angle,and spray particles of the internal mixing air atomizing nozzle Research on the characteristics of diameter and size distribution,and the results show that increasing the liquid flow rate under the same air-liquid mass flow ratio(ALR)or increasing the ALR under the same liquid flow rate will aggravate the degree of liquid fragmentation,and the droplet size will become smaller.The liquid atomization effect becomes better.During an atomization process,the liquid film model in Sun Yuan’s paper was optimized,and the liquid film thickness values under the three liquid flow rates in this paper were calculated by programming.Secondly,the primary fragmentation model in Sun Yuan’s thesis was optimized,and the calculation results of the two models before and after optimization were compared with the experimental values.It was found that the optimized surface wave model in this paper can more accurately predict the droplets after the primary fragmentation of the liquid Sauter Mean Diameter(SMD).In the secondary atomization process,the FLUENT software was used to conduct a numerical simulation study on the secondary atomization process.In the simulation calculation,the droplet SMD calculated in the primary atomization and the test condition parameters were used as input parameters for the simulation calculation,and the internal The distribution characteristics of the droplet size and droplet velocity downstream of the mixed air atomization nozzle show that the influence of ALR on the velocity in the jet field is more significant than that of the liquid flow rate.The change of the droplet size along the axial distance is a first In the process of increasing after decreasing,the simulation results of the model used in the secondary atomization are consistent with the experimental results of this paper.