Numerical analysis of aerosol pool scrubbing mechanisms in rising bubbles using a coupled VOF–DPM framework

During severe nuclear reactor accidents, radioactive aerosols released from degraded fuel can be transported into engineered safety systems such as suppression pools and filtered containment venting systems (FCVS), where water pool scrubbing plays a critical role in retaining aerosols and reducing environmental release. Accurate simulation of aerosol capture mechanisms in such systems is essential for risk-informed safety design and source term quantification. In this study, a two-dimensional coupled Volume of Fluid–Discrete Phase Model (VOF–DPM) was developed to simulate aerosol capture inside rising bubbles. The model resolves gas–liquid interface deformation and particle–interface interactions under transient conditions. Simulation results for both single and side-by-side bubble configurations reveal the dynamic coupling between bubble shape evolution, wake vortex shedding, and aerosol removal efficiency. Parametric analyses show that bubble deformation and unsteady wake flow enhance particle entrainment and deposition on the interface. The interaction between adjacent bubbles further amplifies local turbulence and promotes aerosol capture. Comparison with previously reported experimental and numerical data demonstrates good agreement, confirming the predictive capability of the proposed framework. The present work provides mechanistic insights into the aerosol pool scrubbing process and establishes a predictive modeling approach applicable to suppression pool and FCVS conditions. It contributes to improving the reliability of source term assessment and supports the design optimization of passive containment filtration strategies in advanced nuclear systems.