Do you smell what I smell? How nasal geometry affects airflow dynamics
Do you smell what I smell? How nasal geometry affects airflow dynamics lead image
The anatomy of our nasal cavity is extremely complex and plays a crucial role in how we smell. Because our noses are so diverse in shape and size, improved knowledge of these subtle differences can help further the goal of personalized medicine and health equity. Recent work by Van Strien et al. confirmed the applicability of a particular nasal airflow model with experimental data.
Despite the significant variation in nasal geometries, the authors found a number of flow features common across all noses. In particular, the flow at the vestibule – the entrance to the nose – exhibits swirling features, which contribute to the nose’s particle filtration. As the high-velocity jets from the left and right nasal valves converge in the back of the nasal cavity, the mixing produces a large amount of turbulence. The flow rate and nasal geometry and shape also impact this turbulence.
Working with an ear, nose, throat specialist, the group constructed a model of a volunteer’s nasal cavity and evaluated its airflow properties at constant flow rates between 10 and 30 L/min, representing different inhalation intensities. They compared this with fluid dynamics simulations which adequately capture the turbulence.
“This will help us advance our understanding of nasal physiology – how the nose conditions the inhaled air to near-alveola conditions for respiration in the lung, how the nose allows olfaction to occur, but yet filters out harmful inhaled particles,” said author Kiao Inthavong.
Understanding this interplay can aid the design of targeted drug delivery methods that enter the bloodstream through the nasal mucus or enter the brain via the olfactory nerves.
Source: “Pressure distribution and flow dynamics in a nasal airway using a scale resolving simulation,” by James Van Strien, Kendra Shrestha, Sargon Gabriel, Petros Lappas, David F. Fletcher, Narinder Singh, and Kiao Inthavong, Physics of Fluids (2021). The article can be accessed at https://doi.org/10.1063/5.0036095 .
