Choice of scattering particles during measuring turbulent flow field with particle dynamic analyzer

The technology of laser Doppler velocity measurement in fluid depends on the presence of suitable particles. How to choose the scattering particles during mea-suring turbulent flow field with particle dynamic analyzer(PDA)is discussed in this pa-per.The results show:(1)The choice of scattering particle is the main factor of influe-ncing the velocity measurement;(2)In the study of turbulent flow field by PDA,the requirements of scattering particle choice are mainly small size,low particle density,high particle refractive index and suitable concentration.