人体上呼吸道模型内气流和颗粒沉积的大涡模拟

Large-eddy simulation of airflow and particle deposition in a human upper airway model

为探索人体呼吸道内的气体流动和颗粒的运动沉积规律,建立了一个从口腔到前三级支气管的三维几何模型,采用大涡模拟方法计算了此复杂几何结构内的气体流动,并在拉格朗日框架下研究了颗粒的运动现象.讨论了在呼气和吸气过程中不同横截面的流动分布规律,统计了在不同工况下颗粒在呼吸道模型内各部位的沉积率.分析结果表明,不同级气管横截面的流动结构存在很大差异,颗粒沉积率主要受到呼吸强度与颗粒惯性的影响.为验证模型和模拟结果的正确性,将模拟得到的沉积率和文献中的实验数据进行了比较,两者吻合良好.

A three-dimensional geometry model from mouth to fore-three-generation bronchi was built to investigate the airflow and particle deposition in human respiratory tract. Large-eddy simulation of airflow in this complex geometry model which representing human upper airway was conducted, and the particle transport was studied under Lagrange frame. Then the airflow distributions at the cross sections of different generation trachea during inhalation and exhalation were discussed, and the particle deposition efficiency in various regions under different cases was predicted and analyzed. The results showed very different airflow structure at the cross sections of different generation trachea during inhalation and exhalation, and the particle deposition efficiency was impacted by the inflow velocity and particle inertia. The particle deposition efficiency from model prediction and experimental data agreed well, which validated the correctness of the mathematical model and simulation.