Validation of computational fluid dynamics methodology used for human upper airway flow simulations
Validation of computational fluid dynamics methodology used for human upper airway flow simulations
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DOI：
10.1016/j.jbiomech.2009.03.035
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发表时间：
2009-07-22
影响因子：
2.4
通讯作者：
Gutmark, Ephraim
中科院分区：
文献类型：
--
作者：
Mylavarapu, Goutham;Murugappan, Shanmugam;Gutmark, Ephraim
从多个磁共振成像轴向扫描构造解剖学上精确的人体上气道模型。该模型用于在呼气期间进行详细的计算流体动力学（CFD）模拟，以研究可能发生阻塞的气道区域中的流体流动。使用立体光刻法建立了同一气道的相同物理模型。在物理模型中进行压力和速度测量。模拟和实验均在呼气峰流速为200 L/min时进行。模拟中使用了FLUENT商业软件框架内的几种不同数值方法;非定常大涡模拟（LES），定常雷诺平均Navier-Stokes（RANS）双方程湍流模型（即k-ω、标准k-ω和k-ω剪切应力传输（SST））和单方程Spalart-Allmaras模型。沿气道壁沿着不同位置处的平均壁静压的CFD预测与实验数据进行了有利的比较。在所有方法中，标准k-Ω湍流模型与静压测量结果的一致性最好，所有端口的平均误差接近20%。最高的正压在会厌下方的舌后区，而最低的负压记录在腭后区。后者是气流在腭后狭窄区域加速的结果。最大的压力降在软腭的顶端观察到。该位置具有气道的最小横截面。计算结果与实验结果吻合较好，表明CFD模拟可以用来准确计算上气道的气动流动特性。(C)2009爱思唯尔有限公司保留所有权利。
An anatomically accurate human upper airway model was constructed from multiple magnetic resonance imaging axial scans. This model was used to conduct detailed Computational Fluid Dynamics (CFD) simulations during expiration, to investigate the fluid flow in the ail-way regions where obstruction could occur. An identical physical model of the same airway was built using stereo lithography. Pressure and velocity measurements were conducted in the physical model. Both simulations and experiments were performed at a peak expiratory flow rate of 200 L/min. Several different numerical approaches within the FLUENT commercial software framework were used in the simulations; unsteady Large Eddy Simulation (LES), steady Reynolds-Averaged Navier-Stokes (RANS) with two-equation turbulence models (i.e. k-epsilon, standard k-omega, and k-omega Shear Stress Transport (SST)) and with one-equation Spalart-Allmaras model. The CFD predictions of the average wall static pressures at different locations along the airway wall were favorably compared with the experimental data. Among all the approaches, standard k-omega turbulence model resulted in the best agreement with the static pressure measurements, with an average error of similar to 20% over all ports. The highest positive pressures were observed in the retroglossal regions below the epiglottis, while the lowest negative pressures were recorded in the retropalatal region. The latter is a result of the airflow acceleration in the narrow retropalatal region. The largest pressure drop was observed at the tip of the soft palate. This location has the smallest cross section of the airway. The good agreement between the computations and the experimental results suggest that CFD simulations can be used to accurately compute aerodynamic flow characteristics of the upper airway. (C) 2009 Elsevier Ltd. All rights reserved.