人体上呼吸道内气流运动特性的数值模拟分析

运用计算流体动力学(CFD)方法对人体上呼吸道内的气流运动特性进行了数值模拟,通过PIV实验对数值模拟结果进行了验证。研究结果表明:气流在咽部外壁、气管外壁发生分离现象,气流在气管内壁形成局部高速区,支气管内的气流在分叉处发生分离,靠近支气管内壁速度较高,并且在支气管边界层的外缘速度达到最大值。气管和支气管内的二次涡流运动和轴向速度的分布使得气管支气管内壁受到的剪应力较大,内壁粘膜更容易受到损伤。

Numerical simulation for airflow movement in the human upper respiratory tract

The CFD (Computational Fluid Dynamic) technology was used to investigate the air movement within the human upper respiratory tract. The simulation results were validated by the experimental results based on the PIV (Particle Image Velocimetry) experiment. The results show that the phenomenon of airflow separation appears near the outer wall of the pharynx and the trachea. The high velocity zone is created near the inner wall of the trachea. The airflow splits at the divider and high velocity zone is generated near the inner wall of the trachea. The maximum velocity appears at the exterior of the boundary layer. The secondary swirls and axial velocity distribution result in the high shearing stress acting on the inner wall of the trachea and bifurcation, finally lead to injury on the inner wall.