Modelling aerosol evolution under quiescent and turbulent conditions using a coupled fluid-particle dynamics solver incorporating fractal morphology.

UNLABELLED: Aerosolved, an existing CFD–population balance solver for aerosol dynamics, is extended in this work through an enhanced module, Aerosolved-Sf, to incorporate turbulence-enhanced coagulation and fractal aggregate morphology. The upgraded framework is validated against experiments conducted in the nuclear aerosol test facility under both quiescent and fan-induced turbulent conditions. Under quiescent conditions, simulations assuming spherical particles under predict peak mass concentrations by ~ 40% and overestimate removal rates; the predicted decay constants at the lower port (LP) and upper port (UP) are 9.5 × 10− 5 s− 1 and 2.2 × 10− 4 s− 1 respectively, compared with the measured value of 3.0 × 10− 5 s− 1 (LP) and 5.5 × 10− 5 s− 1 (UP). Incorporating fractal morphology (fractal dimension = 1.8) reduces the decay constants to 2.5 × 10− 5 s− 1 (LP) and 7.6 × 10− 5 s− 1 (UP), significantly lowering statistical bias at both sampling locations. The model reproduces the observed peak–plateau–decay behaviour and vertical stratification of aerosol mass concentration spanning nearly one order of magnitude. Under turbulent conditions (5% intensity), predicted steady concentrations of 0.075 g.m− 3 (LP) and 0.06 g.m− 3 (UP) are in close agreement with measurements. These results demonstrate that realistic representation of aggregate morphology and turbulence is essential for accurate prediction of aerosol residence time, stratification, and mass decay in confined environments.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1038/s41598-026-46277-4.