Study On Spray Atomization Characteristics Based On Laser Measurement

With a wide application in spray,with the increasing production efficiency in the production and life,the performance of the nozzles and atomization characteristics of nozzles have been paid more and more attention by researchers both at home and abroad.The atomization characteristics of the spray include flow distribution,particle size distribution,spray uniformity and so on,its advantages and disadvantages will affect the ignition,combustion efficiency,temperature distribution,combustion stability,chemical reaction contact area,exhaust pollution and other aspects.In this paper,the atomization characteristics of the nozzle were studied in two parts.First,by utilizing a single-phase nozzle flow distribution testing system and the LS-2000 laser particle size analyzer,an experimental study was conducted of the flow distribution performance and the atomization characteristics of spiral surface large discharge and low pressure nozzles the atomization characteristics of the spiral nozzles with high flow and low backpressure in the pressure range of 0.025-0.035MPa.To analyze the influence of spiral nozzle size parameters on flow distribution and particle size distribution of spiral nozzles.The flow rate distribution,the spray volume,the radial volume flow rate,the characteristic diameter and the droplet size of the spray nozzles at different height and different aperture diameter were measured.The results show that for the same nozzle,the larger the atomization pressure is,the larger the flow rate is,the bigger the atomization angle is,and the farther the distance from the center of the nozzle is,the smaller the characteristic diameter is.At the same pressure,the larger the ratio of the height H to the aperture D,the smaller the flow rate,the bigger the atomization angle,the smaller the volumetric flow rate of the spray surface,the smaller the characteristic diameter and the smaller the particle size distribution curve.Secondly,based on digital holography,combined with high-speed photography,taking ethanol spray as an example,the atomization characteristics of self-built microfluidic nozzle were studied,and the effects of liquid flow rate(LFR)/air flow rate(AFR)on atomization characteristics such as penetration distance,spray cone angle,droplet number distribution,volume distribution,characteristic diameter,uniformity,axial distribution and radial distribution of particle size.The results show that when the liquid flow rate is small(1 mL/min),the spray angle and D32 increase with the increase of the gas flow rate,but when the liquid flow rate is larger(2 mL/min and 3 mL/min),the spray angle,D32 decreased with the increase of gas flow rate.An increase in gas flow or liquid flow results in an increase in penetration distance.The number of small droplets and concentrated,more than 250 ?m little.In the axial direction,D32 is the smallest at the nozzle outlet ?Z=120,and the atomization effect is the best.In the radial direction,D32 is symmetrical distribution,first increasing and then decreasing,the density of the droplet density is large near the nozzle centerline.Increasing the gas flow helps to reduce the relative index of the droplet,the atomization is more uniform.