A Computational Fluid Dynamics Study on the Airflow Patterns in Infant and Adult

The nasal cavity evolves with age from birth to adulthood. The airflow dynamics define the productive-ness of the nasal cavity in terms of filtering of the unwanted dust particles, heating, and humidification of inspired air. The study aims to understand and compare the airflow dynamics between infant and adult nasal airways. Com-putational Fluid Dynamics simulation is performed to determine airflow patterns in an infant nasal cavity and com-pare them with an adult nasal cavity. Segmentation of nasal CT scans of healthy infants and adults were performed with MIMICS 21.0 (Materialise, Ann Arbor, MI). These anatomically accurate patient models were simulated for airflow using ANSYS FLUENT 2020 R2. A Mesh dependency check is performed to ascertain the solution is grid-independent. The nasal valve region depicted a peak velocity for both the infant and adult nasal cavity. The effective diameter and the hydraulic diameter of an infant is about 70% to 75% of the adult nasal cavity respectively. The in-fant nasal cavity projects a higher pressure drop and nasal resistance when compared to the adult which is nearly 85% higher at sedentary breathing conditions. The nasal valve experiences the Maximum Wall shear stress which is two times higher for an adult when compared to an infant nasal cavity. The airflow comparison between the infant and adult nasal cavity reveals that the nasal valve region is the location of peak velocity where the adult experiences 80% higher velocity when compared to the infant. Also, infants experience a higher pressure drop and an elevated nasal resistance in comparison to adults. Higher nasal resistance implies the requirement of higher work of breathing. The maximum wall shear stress at the nasal valve is two times higher in adults when compared to the infant nasal cavity.