Unsteady flow through in-vitro models of the glottis

G.C.J. Hofmans, G. Groot, M. Ranucci, G. Graziani, Abraham Hirschberg

Research output: Contribution to journalArticleAcademicpeer-review

84 Citations (Scopus)

Abstract

The unsteady two-dimensional flow through fixed rigid in vitro models of the glottis is studied in some detail to validate a more accurate model based on the prediction of boundary-layer separation. The study is restricted to the flow phenomena occurring within the glottis and does not include effects of vocal-fold movement on the flow.Pressure measurements have been carried out for a transient flow through a rigid scale model of the glottis. The rigid model with a fixed geometry driven by an unsteady pressure is used in order to achieve a high accuracy in the specification of the geometry of the glottis. The experimental study is focused on flow phenomena as they might occur in the glottis, such as the asymmetry of the flow due to the Coanda effect and the transition to turbulent flow. It was found that both effects need a relatively long time to establish themselves and are therefore unlikely to occur during the production of normal voiced speech when the glottis closes completely during part of the oscillation cycle. It is shown that when the flow is still laminar and symmetric the prediction of the boundary-layer model and the measurement of the pressure drop from the throat of the glottis to the exit of the glottis agree within 40%. Results of the boundary-layer model are compared with a two-dimensional vortex-blob method for viscousflow. The difference between the results of the simpiflied boundary-layer model and the experimental results is explained by an additional pressure difference between the separation point and the far field within the jet downstream of the separation point. The influence of the movement of the vocal folds on our conclusions is still unclear.
Original languageUndefined
Pages (from-to)1658-1675
Number of pages18
JournalJournal of the Acoustical Society of America
Volume113
Issue number3
DOIs
Publication statusPublished - 2003

Keywords

  • IR-101608
  • METIS-240198

Cite this

Hofmans, G. C. J., Groot, G., Ranucci, M., Graziani, G., & Hirschberg, A. (2003). Unsteady flow through in-vitro models of the glottis. Journal of the Acoustical Society of America, 113(3), 1658-1675. https://doi.org/10.1121/1.1547459
Hofmans, G.C.J. ; Groot, G. ; Ranucci, M. ; Graziani, G. ; Hirschberg, Abraham. / Unsteady flow through in-vitro models of the glottis. In: Journal of the Acoustical Society of America. 2003 ; Vol. 113, No. 3. pp. 1658-1675.
@article{b0c32c9735bd4f5f9d6f6f5ad023eaec,
title = "Unsteady flow through in-vitro models of the glottis",
abstract = "The unsteady two-dimensional flow through fixed rigid in vitro models of the glottis is studied in some detail to validate a more accurate model based on the prediction of boundary-layer separation. The study is restricted to the flow phenomena occurring within the glottis and does not include effects of vocal-fold movement on the flow.Pressure measurements have been carried out for a transient flow through a rigid scale model of the glottis. The rigid model with a fixed geometry driven by an unsteady pressure is used in order to achieve a high accuracy in the specification of the geometry of the glottis. The experimental study is focused on flow phenomena as they might occur in the glottis, such as the asymmetry of the flow due to the Coanda effect and the transition to turbulent flow. It was found that both effects need a relatively long time to establish themselves and are therefore unlikely to occur during the production of normal voiced speech when the glottis closes completely during part of the oscillation cycle. It is shown that when the flow is still laminar and symmetric the prediction of the boundary-layer model and the measurement of the pressure drop from the throat of the glottis to the exit of the glottis agree within 40{\%}. Results of the boundary-layer model are compared with a two-dimensional vortex-blob method for viscousflow. The difference between the results of the simpiflied boundary-layer model and the experimental results is explained by an additional pressure difference between the separation point and the far field within the jet downstream of the separation point. The influence of the movement of the vocal folds on our conclusions is still unclear.",
keywords = "IR-101608, METIS-240198",
author = "G.C.J. Hofmans and G. Groot and M. Ranucci and G. Graziani and Abraham Hirschberg",
year = "2003",
doi = "10.1121/1.1547459",
language = "Undefined",
volume = "113",
pages = "1658--1675",
journal = "Journal of the Acoustical Society of America",
issn = "0001-4966",
publisher = "Acoustical Society of America",
number = "3",

}

Hofmans, GCJ, Groot, G, Ranucci, M, Graziani, G & Hirschberg, A 2003, 'Unsteady flow through in-vitro models of the glottis' Journal of the Acoustical Society of America, vol. 113, no. 3, pp. 1658-1675. https://doi.org/10.1121/1.1547459

Unsteady flow through in-vitro models of the glottis. / Hofmans, G.C.J.; Groot, G.; Ranucci, M.; Graziani, G.; Hirschberg, Abraham.

In: Journal of the Acoustical Society of America, Vol. 113, No. 3, 2003, p. 1658-1675.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Unsteady flow through in-vitro models of the glottis

AU - Hofmans, G.C.J.

AU - Groot, G.

AU - Ranucci, M.

AU - Graziani, G.

AU - Hirschberg, Abraham

PY - 2003

Y1 - 2003

N2 - The unsteady two-dimensional flow through fixed rigid in vitro models of the glottis is studied in some detail to validate a more accurate model based on the prediction of boundary-layer separation. The study is restricted to the flow phenomena occurring within the glottis and does not include effects of vocal-fold movement on the flow.Pressure measurements have been carried out for a transient flow through a rigid scale model of the glottis. The rigid model with a fixed geometry driven by an unsteady pressure is used in order to achieve a high accuracy in the specification of the geometry of the glottis. The experimental study is focused on flow phenomena as they might occur in the glottis, such as the asymmetry of the flow due to the Coanda effect and the transition to turbulent flow. It was found that both effects need a relatively long time to establish themselves and are therefore unlikely to occur during the production of normal voiced speech when the glottis closes completely during part of the oscillation cycle. It is shown that when the flow is still laminar and symmetric the prediction of the boundary-layer model and the measurement of the pressure drop from the throat of the glottis to the exit of the glottis agree within 40%. Results of the boundary-layer model are compared with a two-dimensional vortex-blob method for viscousflow. The difference between the results of the simpiflied boundary-layer model and the experimental results is explained by an additional pressure difference between the separation point and the far field within the jet downstream of the separation point. The influence of the movement of the vocal folds on our conclusions is still unclear.

AB - The unsteady two-dimensional flow through fixed rigid in vitro models of the glottis is studied in some detail to validate a more accurate model based on the prediction of boundary-layer separation. The study is restricted to the flow phenomena occurring within the glottis and does not include effects of vocal-fold movement on the flow.Pressure measurements have been carried out for a transient flow through a rigid scale model of the glottis. The rigid model with a fixed geometry driven by an unsteady pressure is used in order to achieve a high accuracy in the specification of the geometry of the glottis. The experimental study is focused on flow phenomena as they might occur in the glottis, such as the asymmetry of the flow due to the Coanda effect and the transition to turbulent flow. It was found that both effects need a relatively long time to establish themselves and are therefore unlikely to occur during the production of normal voiced speech when the glottis closes completely during part of the oscillation cycle. It is shown that when the flow is still laminar and symmetric the prediction of the boundary-layer model and the measurement of the pressure drop from the throat of the glottis to the exit of the glottis agree within 40%. Results of the boundary-layer model are compared with a two-dimensional vortex-blob method for viscousflow. The difference between the results of the simpiflied boundary-layer model and the experimental results is explained by an additional pressure difference between the separation point and the far field within the jet downstream of the separation point. The influence of the movement of the vocal folds on our conclusions is still unclear.

KW - IR-101608

KW - METIS-240198

U2 - 10.1121/1.1547459

DO - 10.1121/1.1547459

M3 - Article

VL - 113

SP - 1658

EP - 1675

JO - Journal of the Acoustical Society of America

JF - Journal of the Acoustical Society of America

SN - 0001-4966

IS - 3

ER -

Hofmans GCJ, Groot G, Ranucci M, Graziani G, Hirschberg A. Unsteady flow through in-vitro models of the glottis. Journal of the Acoustical Society of America. 2003;113(3):1658-1675. https://doi.org/10.1121/1.1547459