[Numerical simulation on cycle change form of the pressure and wall shear in human upper respiratory tract].

The research on cycle change form of the pressure and the wall shear in human upper respiratory tract can strengthen understanding of the characteristics of the airflow in the place and provide us with a scientific basis for analyzing the diffusion, transition and deposition patterns of aerosol there. In our study, we used large eddy simulation to emulate the pressure and wall shear in human upper respiratory tract in conditions of the low intensive respiratory patterns, and discussed the distributing disciplinarian of the pressure and wall shear in mouth-throat model and trachea-triple bifurcation. The results showed that the pressure gradient variation in human upper respiratory tract was mainly fastened from root of epiglottis to trachea. The minimum pressure at the interim of inspiration was a duplication of the interim of expiration, and located on the posterior wall of the glottis. The pressure gradient variation was evident on trachea and its fork. The wall shear changed with the velocity of the air flow, and its direction changed periodically with breath cycle.