真实人体鼻腔三维重建和气流特性的数值模拟

为研究人体鼻腔内的气体流动和颗粒沉积状况,基于19岁男志愿者的螺旋CT医学图像,采用医学有限元方法和逆向工程技术,重构了真实人体鼻腔的三维几何模型.采用RNG k-ε湍流模型和有限差分数值方法对志愿者在Q=15 L/min(人体平静时刻)、Q=30 L/min(小负荷运动时刻)、Q=60 L/min(大负荷运动时刻)三种呼吸强度下的鼻腔内的气体流动特性进行了数值模拟与分析,得到了呼吸时鼻腔内的压力和气流分布规律,并在拉格朗日框架下跟踪了颗粒的运动和沉积.以3μm粒径颗粒为研究对象,可视化显示了其在鼻腔内的沉积位置.本研究对呼吸时人鼻腔中气体流动特性、气雾剂治疗等问题深入探讨具有参考价值.

3D RECONSTRUCTION AND NUMERICAL SIMULATION OF AIRFLOW CHARACTERISTICS IN REALISTIC HUMAN NASAL CHANNEL

In order to research the airflow and particle deposition inside a nasal channel,a real three-dimensional geometry of human nasal channel is rebuilt with a direct deal with original spiral CT(computer tomography)respiratory tract images scanned from a voluntary healthy 19-years old boy and with image recognition technology such as finite element method and reverse engineering.Based on the rebuilt geometric model.RNG k-ε model and finite volume method is used to simulate and analyze the gas flow at three different respiratory rate as Q=15 L/min,Q=30 L/min and Q=60 L/min.The pressure and airflow velocity during inspiration and exhalation inside the nasal channel at different airflow rates is computed and discussed.The particle is tracked and analyzed in a Lagrangian frame.The trapping of particles with a diameter of 3 μm on the wall surfaces is monitored.The numerical simulation can help study the characters of airflow in the nasal channel and aerosol therapy.