Y型喷嘴反压环境粒径的图像捕捉测量技术

鉴于Y型喷嘴反压条件下的粒径难以采用传统光学测量手段获得有效数据,提出一种基于图像捕捉的粒径处理程序,通过微距镜头拍摄雾场图像,通过图像识别和数据统计获取有效索太尔平均直径（SMD）。该处理方法在大气下与相位多普勒粒子分析仪(PDPA)测量结果误差不超过12%。实验结果表明:在反压条件下,当气流量为0g/s时,雾化粒径较大,随着环境压力升高和液流量增大,雾化粒径呈减小趋势；当加入气流量为55g/s时,雾化粒径显著降低,并且粒径随着环境压力升高而增大(该结果与不加气时恰恰相反),而在同一反压、不同液流量工况下,雾化粒径基本保持不变。在燃烧室变工况条件下,加入少量的气体即可使雾化粒径显著减小且在变工况条件下基本保持一致。 

Granulometric technique by photographic methods ofY jet nozzles under back pressure condition

As its hard to achieve useful data by optical measurement granulometric technique of Y jet nozzle in back pressure condition, a photographic method depending on morphology was put forward to get detailed data of the Sauter mean diameter (SMD). The error among photographic methods and phase Doppler particle analyzer (PDPA) was less than 12%. The experimental results indicated that SMD decreased with air flow rate of 0g/s and increased with air flow rate of 55g/s along with pressure rising and flow rate growing under back pressure condition. SMD almost stayed the same by different flow rates under the same pressure condition with air joining. Finally through tests by simulating real variable condition process in combustion chamber, it was concluded that SMD under variable pressure condition was almost the same with little air joining in nozzle.