离心式喷嘴在小尺度受限空间雾化特性的实验研究

Experiment Study on Spray Characteristics of the Swirl Injector in Small Scale Chamber

关键词:  小尺度空间  离心式喷嘴  雾化  周向分布 

Key words:  Small scale space  Swirl injector  Atomization  Circumferential distribution

摘要:

为了了解小尺度受限空间中离心式喷嘴的雾化特性,设计了四旋流槽离心式喷嘴和小尺度模拟燃烧室,采用相位多普勒粒子动态分析仪(PDA),观测了喷射压力对模拟燃烧室内雾化性能的影响。引入离散系数cv对喷雾场雾化参数的周向分布规律进行了着重分析。结果表明:模拟燃烧室内,喷射压力越大,液滴索特尔平均直径D32的值越小；在z∈[41.5,4.2]的轴向距离范围内,喷射压力对v_z的影响不明显。由于壁面作用,液滴D32的周向分布均匀性随着径向距离的增加变差；距离喷嘴出口越远处,液滴D32的周向分布均匀性越好。在喷射压力相同条件下,同一喷嘴在模拟燃烧室内雾化参数的周向分布均匀性比在大气环境中波动更大。 

Abstract:

To investigate the spray distribution characteristics of the swirl injector in small scale space,a swirl injector with four swirl slots and a simulated small scale chamber were designed. The effects of the injection pressure on the spray parameters in the simulated combustion chamber were studied by using of the PDA system. The circumferential distribution of the spray field was emphasized using the coefficient of variation (cv). The results indicate that the greater the injection pressure, the smaller the liquid droplets D32(Sauter Mean Diameter). For the studied range of axial distance, the effect of the injection pressure on the droplets vz(axial velocity) is not obvious. As for the impaction of the chamber wall, the uniformity of the circumferential distribution of D32 is getting worse along the radial direction. The further away from the nozzle exit, the more uniform the circumferential distribution of liquid droplets D32. Under the same injection pressure, the uniformity of the circumferential distribution of the droplets in the chamber is more fluctuating than that in the atmosphere by using the same injector. 