多频声衰减法测量低密度差异液固两相流粒径分布

Measurement of Particle Size Distribution in Liquid-solid Two-phase Flows With Low Density Differences by Multi-frequency Acoustic Attenuation

针对低密度差异液固两相流的分散相粒径分布测量问题,提出多频超声衰减测量方法。以ECAH(Epstein Carhart Allegra Hawley theory)理论模型为基础,分析了不同物性参数对多频超声衰减的影响,建立了分散相粒径分布与多频超声衰减之间的理论关系,用于计算被测流体中超声衰减的理论预测值。通过构造实测多频衰减与待求粒径分布间的目标函数,将粒径分布的反演表示为优化问题,利用高斯量子粒子群算法对不同粒径颗粒浓度参数寻优,实现粒径分布的反演。以微米级聚苯乙烯颗粒与水制备的悬浮液作为研究对象,在搅拌条件下进行动态实验。实验结果表明,利用411 MHz的多频超声衰减测得的粒径分布,与Mastersizer 2000激光粒度分析仪的测量结果基本一致,平均粒径误差为5.60%。

A multi-frequency ultrasonic attenuation method is proposed for the measurement of the particle size distribution of liquid-solid two-phase flow with low density difference.First,the effect of different physical parameters on the ultrasonic attenuation is analyzed based on the theoretical model of ECAH(Epstein Carhart Allegra Hawley theory);then,the relationship between the particle size distribution of the dispersed phase and the multi-frequency ultrasonic attenuation is established based on the acoustic attenuation model;finally,the inversion of the particle size distribution is expressed as an optimization problem,and the Gaussian quantum particle swarm algorithm is used to invert the particle size distribution of the dispersed phase.Experiments were conducted with micron-sized polystyrene particles as the dispersed phase and water as the continuous phase,and the particle size distribution was inverted using multi-frequency attenuation.The results show that the particle size distribution results obtained by multi-frequency ultrasonic attenuation from 4–11 MHz are in general agreement with the results of the Mastersizer 2000 laser particle size analyzer,with an error of 5.60%in the average particle size.