Aerosol particles inside a high-amplitude ultrasonic field can experience an agglomeration process that causes their size distribution to be changed. The overall effect of this process can be measured by the particle diameter growth, in terms for instance of the Aerodynamic Count Median Diameter (ACMD). However, the analysis of a poly-dispersed particle mixture requires a complex evaluation of the aerosol size distribution. In this work a method consisting on fitting the measured aerodynamic particle size distributions by lognormal functions is proposed. The aerosols used in the experiments were composed by SiO2 particles of different sizes: 0.3 μm, 1 μm, and 2.5 μm, with different concentrations and exposed to a intense ultrasonic standing wave field with an average sound pressure level of about 155 dB and a frequency of 21 kHz.
Acknowledgements
This work has been founded by the EU-PASSAM project (Grant agreement No. 323217 – Euratom 7FP).