无限细光束中透射起伏时间相关频谱法高浓度效应的模拟

时间或空间相关透射起伏频谱法是近年发展起来的一种新的颗粒测量方法,它可同时测量颗粒粒径分布和浓度,并可用来进行在线、实时测量。研究表明,随着浓度增大,逐渐增强的高浓度效应会导致测量值越来越严重地偏离理论值。本文采用模拟计算方法讨论无限细光束照射下的时间相关透射起伏频谱法高浓度效应并给出部分实验验证。分析表明,无限细光束照射时的透射起伏相关频谱主要受到层结构效应的影响,颗粒交叠效应不明显,表明为随着颗粒浓度增大,转换函数(特征函数)逐渐偏离低浓度理论值并向无因次相关时间小的方向移动,阶高始终保持不变。

Simulations on High-Concentration Effects of Transmission Fluctuation Spectrometry with Temporal Correlation with Infinitesimally Thin Beam

Transmission fluctuation spectrometry with temporal or sptail correlation is being developed as a new method of particle size analysis,in which the particle size distribution and particle concentration can be measured simultaneously,and real-time online measurements can be realized. As the particle concentration increases,the measured transmission fluctuation spectrum deviates gradually from the theory due to the effects of high particle concentration.The high-concentration effects of transmission fluctuation spectrometry with temporal correlation(TFS-TC) are studied with numerical simulation whereby an infinitesimally thin beam is employed and some experimental evidence is also presented.As a result,the correlation spectrum is affected only by the monolayer structure.As the particle concentration increases,the transition function deviates from the theory and shifts to the range of smaller dimensionless correlation time gradually,the step height of the trasition function is unchanged.