CFD analysis of the flow structure in a monkey upper airway validated by PIV experiments

Area of Science:

• Comparative Anatomy
• Respiratory Physiology
• Computational Fluid Dynamics

Background:

• Animal models are used for inhalation exposure research.
• Differences in respiratory tracts complicate human extrapolation.
• Understanding airflow transport mechanisms is crucial.

Purpose of the Study:

• To detail the airflow structure in a monkey's upper airway.
• To provide a basis for more accurate human risk assessment.
• To investigate airflow dynamics relevant to contaminant transport.

Main Methods:

• Utilized steady computational fluid dynamics (CFD) simulation.
• Validated CFD model with particle image velocimetry data.
• Analyzed airflow from nasal/oral cavities to the trachea at 4 and 10 L/min.

Main Results:

• The low Reynolds number k-ε model accurately predicted airflow.
• Significant velocity gradients were observed in the nasal vestibule and larynx.
• Increased turbulent air kinetic energy and wall shear stress were identified.

Conclusions:

• Detailed airflow patterns in monkey airways were elucidated.
• CFD simulation is a viable tool for respiratory tract airflow analysis.
• Findings highlight regions of high aerodynamic stress in the monkey airway.