Numerical Simulation of Size Distribution of Polydisperse Fine Particles during Heterogeneous Condensation in Water Vapor Environment

Heterogeneous nucleation technology can promote the growth of fine particulate matter, making it easier to remove. To investigate the particle size distribution characteristics of fine particulate matter during heterogeneous growth in a growth tube, this study couples the particle growth process with fluid dynamics and explores the interaction between supersaturation distribution and particle flow. The effects of temperature difference and flow velocity on the spatial distribution of particle size are revealed. The results show that, along the axial direction, particle size remains constant at first and then gradually increases; along the radial direction, particle size increases rapidly before decreasing sharply near the wall; ineffective regions exist both at the inlet and wall, where particles cannot be activated to grow; the temperature difference and flow velocity not only influence particle growth efficiency but also affect the extent of these ineffective regions. This study provides a theoretical basis for optimizing the design of growth tubes, enhancing nucleation regions, and improving the utilization of vapor resources.