Semi-empirical model for resuspension of multilayer sedimentary aerosols in pipes

• Multilayer resuspension experiments are conducted in a pipe flow facility with purge gas Re numbers from 50,000 to 130,000. • An S-Logistic relationship is found between dimensionless particle diameter and multilayer aerosol resuspension rate. • A semi-empirical model is established and validated for multilayer aerosol resuspension prediction. As a critical phenomenon influencing radioactive release assessment during nuclear severe accidents, aerosol resuspension requires in-depth investigation, as it can affect the accuracy of radioactive release source term assessment. An experimental apparatus has been established and the resuspension of multi-layered sedimentary aerosols have been conducted under turbulent airflow conditions with Reynolds number ranging from 50,000 to 130,000. The experiments indicate that higher friction velocity of turbulent pipe and larger deposited particle size both increase the resuspension rate. Through mechanical fulcrum model analysis, the resuspension characteristics, which encompass the coupling effects of airflow characteristics, particle characteristics and wall characteristics, are revealed by the dimensionless particle diameter d p + and critical dimensionless particle diameter d p 50 + . A semi-empirical aerosol resuspension model satisfying the S-Logistic function relationship is obtained and validated with multiple sets of experimental data, and showing good agreement between the model predictions and the experimental results.