Zhu Zhenshan, Zhang Chuhua, Zhang Li
Department of Fluid Machinery and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China.
Department of Fluid Machinery and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China; State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China.
Respir Physiol Neurobiol. 2019 Apr;262:40-48. doi: 10.1016/j.resp.2019.01.012. Epub 2019 Jan 30.
The respiration flow pattern plays a key role in fluid flow, heat and mass transfer in human lung airway. To reveal the complex flow pattern within human lung multiple-generation airway, both the steady inspiration and expiration flows are comprehensively studied using laser Doppler velocimetry technique and computational fluid dynamics method for an idealized human tracheobronchial three-generation airway model at two flow rates, corresponding to an adult male breathing under light activity and moderate exercise conditions, respectively. The comparison of mainstream velocity between the measurements and simulations are generally good. Both of the inspiration and expiration flows are heavily influenced by the combination of geometrical bifurcating/merging, local wall curvature, limited generation length and multi-generation interaction. The mainstream flow is non-uniform and behaves as skewed, double-peaked and M-shaped patterns. The secondary flow is complex and characteristic of Dean-type two-vortex, four-vortex, six-vortex and eight-vortex patterns. This work is of scientific significance for a deep understanding of respiratory flow physics and of certain application values for clinical diagnosis and remedy of respiratory deceases.
呼吸流型在人体肺气道内的流体流动、热量和质量传递中起着关键作用。为了揭示人体多代肺气道内复杂的流型，分别针对对应于成年男性在轻度活动和适度运动条件下呼吸的两种流速，使用激光多普勒测速技术和计算流体动力学方法，对理想化的人体气管支气管三代气道模型的稳定吸气和呼气流动进行了全面研究。测量值与模拟值之间的主流速度比较总体良好。吸气和呼气流动都受到几何分叉/合并、局部壁曲率、有限的段长度和多代相互作用的综合影响。主流流动不均匀，呈现出偏态、双峰和M形模式。二次流很复杂，具有迪恩型双涡、四涡、六涡和八涡模式的特征。这项工作对于深入理解呼吸流动物理学具有科学意义，对于呼吸系统疾病的临床诊断和治疗具有一定的应用价值。
