Evaluating the effects of bronchioles simplification on respirable dust deposition: A combined experimental and CFD-DPM analysis approach

Abstract

The resurgence of black lung disease among miners underscores the pressing need to enhance our understanding of respirable dust deposition mechanisms. This paper critically evaluates the widespread practice of simplifying bronchioles geometries in dust deposition studies, a method commonly employed but often without adequate consideration of its impact on particle–wall interactions and subsequent deposition calculations. Through the integration of experimental setups with computational simulations, this study investigates the behavior of respirable coal dust using Particle Image Velocimetry (PIV) and a specially designed dust wind tunnel equipped with both complex and simplified bronchioles models. Further, this research employs Computational Fluid Dynamics-Discrete Phase Model (CFD-DPM) simulations within ANSYS Fluent, incorporating these diverse models to assess the ramifications of geometrical simplification. A bronchioles wall observing model was introduced to enhance the simulation’s realism by more accurately representing the dynamic interactions between dust particles and bronchioles wall surfaces. The complex model showed about 1.5×higher dust deposition compared to the simplified model. This difference was partially attributed to its larger surface area, with a surface area ratio of approximately 1.92. A correction factor based on this ratio was proposed to enhance the predictive capability of simplified models. This approach not only sheds light on the significant influences of particle size and airway geometry on dust deposition but also challenges the reliability of simplified models in replicating these complex processes. This work contributes valuable insights into improving occupational health safety measures in mining and related industries, highlighting the need for careful consideration of model selection and its implications in environmental health research.