TY - JOUR
T1 - Unsteady behavior of flow in a scaled-up vocal folds model
AU - Krane, Michael
AU - Barry, Michael
AU - Wei, Timothy
N1 - Funding Information:
The authors gratefully acknowledge support from Grant No. 1R01DC054642-0l and from the Institute for Deafness and Other Communication Disorders, National Institutes of Health. In addition we would like to thank J. Petrowski for invaluable assistance with the motion control and with model fabrication issues. We would also like to thank N. Krane for assistance in machining the model.
PY - 2007
Y1 - 2007
N2 - Measurements of the fluid flow through a scaled-up model of the human glottis are presented to determine whether glottal flow may be approximated as unsteady. Time- and space-resolved velocity vector fields from digital particle image velocimetry (DPIV) measurements of the flow through the gap between two moving, rigid walls are presented in four cases, over a range of Strouhal numbers: 0.010, 0.018, 0.035, 0.040, corresponding to life-scale f0 of 30, 58, 109, and 126 Hz, respectively, at a Reynolds number of 8000. It is observed that (1) glottal flow onset is delayed after glottal opening and (2) glottal flow shutoff occurs prior to closure. A comparison between flow through a fully open, nonmoving glottis and that through the moving vocal folds shows a marked difference in spatial structure of the glottal jet. The following features of the flow are seen to exhibit strong dependence on cycle frequency: (a) glottal exit plane velocity, (b) volume flow, (c) vortex shedding rates, and (d) vortex amplitude. Vortex shedding appears to be a factor both in controlling flow resistance and in cycle-to-cycle volume flow variations. All these observations strongly suggest that glottal flow is inherently unsteady.
AB - Measurements of the fluid flow through a scaled-up model of the human glottis are presented to determine whether glottal flow may be approximated as unsteady. Time- and space-resolved velocity vector fields from digital particle image velocimetry (DPIV) measurements of the flow through the gap between two moving, rigid walls are presented in four cases, over a range of Strouhal numbers: 0.010, 0.018, 0.035, 0.040, corresponding to life-scale f0 of 30, 58, 109, and 126 Hz, respectively, at a Reynolds number of 8000. It is observed that (1) glottal flow onset is delayed after glottal opening and (2) glottal flow shutoff occurs prior to closure. A comparison between flow through a fully open, nonmoving glottis and that through the moving vocal folds shows a marked difference in spatial structure of the glottal jet. The following features of the flow are seen to exhibit strong dependence on cycle frequency: (a) glottal exit plane velocity, (b) volume flow, (c) vortex shedding rates, and (d) vortex amplitude. Vortex shedding appears to be a factor both in controlling flow resistance and in cycle-to-cycle volume flow variations. All these observations strongly suggest that glottal flow is inherently unsteady.
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U2 - 10.1121/1.2409485
DO - 10.1121/1.2409485
M3 - Article
C2 - 18247773
AN - SCOPUS:38849105066
SN - 0001-4966
VL - 122
SP - 3659
EP - 3670
JO - Journal of the Acoustical Society of America
JF - Journal of the Acoustical Society of America
IS - 6
ER -