Airflow in the Mouth-Throat-Trachea
The developed airflow features in the human airways determine the fate of inhaled aerosols. The complex geometry of the upper airways, which includes bents, expansions and constrictions, in conjunction with Reynolds numbers in the order of a few thousands (2000-10000) leads to airflow transition to turbulence in the pharynx, larynx and trachea. The generated turbulence structures are convected in the downstream generations before they dissipate and the flow becomes laminar again in about the fifth airway generation. Such complex flow phenomena are challenging for numerical modeling and therefore validation of CFD methods is required. UCY-CompSci and Biofluids laboratory of Technion, Israel Institute of Technology are carrying out a combined in vitro – in silico study aiming to assess the performance of LES and RANS simulations in capturing airflow patterns in a simplified child’s mouth-throat model. Numerical predictions are compared against Tomographic PIV measurements at three steady inhalation flowrates varying from shallow to deep inhalation.