The characteristics of the tracer particles used in water flow field for PIV system

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.