Micron particle deposition in the nasal cavity using the v2–f model

Commercial CFD codes are commonly used to simulate models that involve complicated geometries such as the human nasal cavity. This means that the user has to work within the limitations of the available models of the CFD code. One such issue is the turbulent dispersion of particles in the Lagrangian reference, namely the Discrete Random Walk (DRW) model which overpredicts the deposition of smaller inertial particles, due to its inherent isotropic treatment of the normal to the wall fluctuation, v′v′, in the near wall region. DNS data for channel flows has been used to create a function that reduces the turbulent kinetic energy (TKE) to match the v′v′ profile which has delivered improved particle deposition efficiency results. This paper presents an alternative approach to reduce the TKE to match v′v′, by directly taking the profile from the v2–f turbulence model. The approach is validated against experimental pipe flow for a 90° bend and then applied to particle dispersion in a human nasal cavity using Ansys-Fluent which showed improved results compared to no modification.

► A ν2–f   model was used to obtain the ν′ν′ value in the flow field.
► A modification of kmodified=3ν2/2kmodified=3ν2/2 based directly from the ν2–f model was used.
► The modification improved the deposition efficiency for smaller inertial particles.