【摘要】 粒子图像测速技术(PIV)是一种新的流场测量技术,通过对流场中的示踪粒子进行多次曝光成像,获得具有相关性的示踪粒子图像,利用软件对粒子图像进行处理后可得到被测流场的信息。水流场PIV测量利用合适的示踪粒子运动来表征流场状况,示踪粒子的特性对PIV最终测量结果影响很大。讨论了密度、直径、表面反射率等示踪粒子特性对系统实验测量的影响,并特别针对水流场斜入射离轴PIV测试,选择合适的特性参数设计研制了一种简单实用的水流场示踪粒子。通过在直径为100~200μm的聚苯乙烯微球上利用化学方法进行表面镀银,使示踪粒子具有高的光散射特性,实验结果表明这种微粒非常适合于水流场示踪。更多还原

【Abstract】 A novel flow measurement technology,particle image velocimetry(PIV) system is introduced,which is used in water flow field display and measurement. Such PIV system takes pictures of tracer particles twice or more and uses software processing the particle images to get the flow field information.So the characteristics of the particle such as its density,diameter and reflectivity are important to improve the PIV detecting precision.By analyzing these characteristics of tracer particles,polystyrene particle,100～200μm,is chosen to use as the tracer particle for water flow field.Silver coating is formed on the surface of the particles by chemical method to increase the reflectivity.The experiment results show that such tracer particle is very suitable for water flow field tracing.更多还原