Validation of a Numerical Method for Assessment of Human Nasal Air Flow

This paper describes an experimental investigation of the flow through an anatomically accurate model of the left nasal passage of a healthy adult male. Flow visualisation, pressure loss and particle image velocimetry (PIV) measurements are reported. The data obtained from these tests is used to validate a computational fluid dynamics method. For a typical mesh of about one million tetrahedral cells, the flow rate versus pressure drop characteristic can be modelled to within 6%. Laminar flow conditions predominate at resting breathing rates but even at higher breathing rates, the assumption of laminar flow does not appear to reduce greatly the accuracy of the predictions. Favourable comparison has been obtained between the PIV measurements and numerical predictions. The flow in the post-nasal space and naso-pharynx is dominated by a separation at the distal end of the nasal floor, a streamwise vortex and a large region of recirculating flow that forms along the inner wall of the naso-pharynx. Good agreement between the measurements and predictions in this downstream region of the flow gives confidence in the fidelity of the predictions upstream in the nasal cavity.