摘要
在11、12和15MPa射流压力下对环形自由水射流流场进行实验研究,以获得该射流场的能量特征与液滴尺寸分布规律。运用相位多普勒粒子测速(PDPA)技术对射流流场中的速度分布和液滴粒径分布进行测量,并对通过不同位置控制体的单个液滴行为进行了统计分析。研究表明:环形射流流束中心存在着较宽的高速区域,且射流能量沿着射流方向衰减缓慢;距离喷嘴的轴向距离越大,射流横断面上的速度与液滴粒径分布越平坦;射流压力对流束中心的轴向速度变化影响较大,对液滴粒径分布的影响不明显;射流流束中心区的湍流脉动较弱,但通过位于射流中心位置的控制体的液滴粒径谱较宽。
Under jet pressures of 11,12 and 15MPa,free water jet discharged from an annular nozzle was experimentally studied.The objective is to obtain energy distribution and droplet diameter distribution in the jet flow field.Phase Doppler Particle Anemometry(PDPA) was applied in measurement of velocity and droplet diameter distributions.Statistical analysis of those droplets passing through control volumes at different locations was performed.The results indicate that a relatively wide high-velocity zone exists near the jet axis and energy dissipation is slow along the jet direction.Both velocity and droplet diameter distributions get smoother when the distance between the transverse section and the nozzle becomes larger.Jet pressure has a comparatively evident influence on velocity increase near the jet axis.But the impact exerted on droplet diameter distribution by increase of jet pressure is unremarkable.Weak turbulent fluctuation occurs near the jet axis where droplet diameter covers a wide range.
出处
《实验流体力学》
EI
CAS
CSCD
北大核心
2011年第1期7-12,共6页
Journal of Experiments in Fluid Mechanics
基金
国家自然科学基金资助项目(50806031)
关键词
环形射流
PDPA
脉动速度
粒径
控制体
统计方法
annular jet
PDPA
fluctuating velocity
droplet diameter
control volume
statistical method
