Effect of net surface charge on particle sizing and material recognition by using phase Doppler anemometry.
By taking net surface charge into consideration, the scattering field of particles illuminated by dual laser beams of phase Doppler anemometry (PDA) is computed based on Mie's theory, and the effect of net surface charge on the phase-diameter relationship and the phase ratio is studied. It is found that the phase-diameter relationship and the relationship between the phase ratio and the refractive index of charged particles could be significantly different from those of uncharged particles, which would lead to errors in particle sizing and the measurement of refractive indices. A method of recognizing charged particles and determining the value of their surface conductivity, which is related to net surface charge, is proposed by utilizing the effect of net surface charge on the measurement of refractive indices using PDA.
Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University, Ministry of Education, Lanzhou, Gansu 730000, China. zhoujun@lzu.edu.cn
Jun
J
Zhou
Li
L
Xie