Micron Particle Deposition in the Nasal Cavity Using the v ²-f Model

Abstract

From a health perspective inhaled particles can lead to many respiratory ailments. In terms of modelling, the introduction of particles involves a secondary phase (usually solid or liquid) to be present within the primary phase (usually gas or liquid). The influence of the fluid flow regime, whether it is laminar or turbulent plays a significant role on micron particle dispersion. RANS (Reynolds Averaged Navier-Stokes) based turbulence models provide simpler and quicker modelling over the more computationally expensive Large Eddy Simulations. However this comes at an expense in that the RANS models fails to resolve the near wall turbulence fluctuating quantities due to the turbulent isotropic assumption. This error further propagates to the Lagrangian particle dispersion. Using the v ²-f the normal to the wall turbulent fluctuation, can be solved and used on the particle dispersion model directly in order to overcome the isotropic properties of RANS turbulence models. This technique is first validated against experimental pipe flow for a 90^°-bend and then applied to particle dispersion in a human nasal cavity using Ansys-Fluent. The results arising from the nasal cavity application will increase the understanding of particle deposition in the respiratory airway. Greater knowledge of particle dynamics may lead to safer guidelines in the context of exposure limits to toxic and polluted air.