Luo H Y, Liu Y
Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
J Biomech. 2008 Aug 28;41(12):2681-8. doi: 10.1016/j.jbiomech.2008.06.018. Epub 2008 Jul 29.
The inspiratory flow characteristics in a CT-scanned human lung model were numerically investigated using low Reynolds number (LRN) kappa-omega turbulent model. The five-generation airway is extracted from the trachea to segmental bronchi of a 60-year-old Chinese male patient. Computations were carried out in the Reynolds number range of 900-2100, corresponding to mouth-air breathing rates of 190-440 ml/s. Flow patterns on the Re=2100 and flow rate distribution were presented. In this model, the flow pattern is very complex. To count the effect of laryngeal jet on trachea inlet, the trachea was extended and modified to simulate the larynx, consequently the inlet velocity profile is biased towards the rear wall. In the inferior lobar bronchi, there are two stems in which the axial velocity is stronger but secondary velocity is weaker. Secondary flow in the lateral bronchi is stronger than the medial ones. With increasing Re, the air flow increases in the middle, inferior lobes and left main bronchus, i.e., flow biases to left and downward.
使用低雷诺数（LRN）κ-ω湍流模型对CT扫描的人体肺部模型中的吸气流动特性进行了数值研究。从一名60岁中国男性患者的气管到段支气管提取了五级气道。计算在雷诺数900 - 2100范围内进行，对应于190 - 440 ml/s的口腔空气呼吸速率。给出了Re = 2100时的流动模式和流量分布。在该模型中，流动模式非常复杂。为了考虑喉喷流对气管入口的影响，对气管进行了延伸和修改以模拟喉部，因此入口速度剖面偏向后壁。在下叶支气管中，有两个分支，其中轴向速度较强但二次速度较弱。外侧支气管中的二次流比内侧支气管中的强。随着雷诺数的增加，中、下叶和左主支气管中的气流增加，即气流向左下方偏斜。
