Farbos de Luzan Charles, Chen Jie, Mihaescu Mihai, Khosla Sid M, Gutmark Ephraim
Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, Ohio 45221-0070, United States.
Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, Cincinnati, Ohio 45221-0070, United States.
J Biomech. 2015 May 1;48(7):1248-57. doi: 10.1016/j.jbiomech.2015.03.010. Epub 2015 Mar 19.
Compressible large eddy simulation is employed to numerically investigate the laryngeal flow. Symmetric static models of the human larynx with a divergent glottis are considered, with the presence of false vocal folds (FVFs). The compressible study agrees well with that of the incompressible study. Due to the high enough Reynolds number, the flow is unsteady and develops asymmetric states downstream of the glottis. The glottal jet curvature decreases with the presence of FVFs or the ventricular folds. The gap between the FVFs stretches the flow structure and reduces the jet curvature. The presence of FVFs has a significant effect on the laryngeal flow resistance. The intra-glottal vortex structures are formed on the divergent wall of the glottis, immediately downstream of the separation point. The vortices are then convected downstream and characterized by a significant negative static pressure. The FVFs are a main factor in the generation of stronger vortices, and thus on the closure of the TVFs. The direct link between the FVFs geometry and the motion of the TVFs, and by extension to the voice production, is of interest for medical applications as well as future research works. The presence of the FVFs also changes the dominant frequencies in the velocity and pressure spectra.
采用可压缩大涡模拟对喉部气流进行数值研究。考虑了具有发散声门的人类喉部对称静态模型，以及假声带（FVFs）的存在。可压缩研究与不可压缩研究结果吻合良好。由于雷诺数足够高，气流不稳定，在声门下游发展为不对称状态。声门射流曲率随着FVFs或室襞的存在而减小。FVFs之间的间隙拉伸了流动结构并减小了射流曲率。FVFs的存在对喉部流动阻力有显著影响。声门内涡旋结构在声门发散壁上、分离点下游立即形成。这些涡旋随后向下游对流，并具有显著的负静压特征。FVFs是产生更强涡旋的主要因素，从而影响声带（TVFs）的闭合。FVFs几何形状与TVFs运动之间的直接联系，进而与语音产生的联系，对医学应用以及未来的研究工作都具有重要意义。FVFs的存在还改变了速度和压力谱中的主导频率。
