Quantification of the Intraglottal Pressure Induced by Flow Separation Vortices Using Large Eddy Simulation
| Autor: | Ephraim Gutmark, Sid Khosla, Liran Oren, Charles Farbos de Luzan |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Glottis
Vocal Cords Article 030507 speech-language pathology & audiology 03 medical and health sciences Speech and Hearing Flow separation 0302 clinical medicine Phonation Pressure medicine Humans 030223 otorhinolaryngology Closing (morphology) Physics Maximum flow problem Mechanics LPN and LVN Vortex medicine.anatomical_structure Otorhinolaryngology Vocal folds Larynx 0305 other medical science Large eddy simulation |
| Zdroj: | J Voice |
| ISSN: | 0892-1997 |
| Popis: | Summary The greatest rate of change in the glottal flow rate during phonation is a rapid decrease that occurs during the latter part of the glottal closing. Previous works showed that intraglottal flow separation vortices form in a divergent glottis, produce negative gauge pressures (below atmospheric) during closing. It is hypothesized here that flow separation vortices contribute to the rapid closing mechanism of the true vocal folds during phonation. Four idealized static models (M5) of the human larynx were investigated using large eddy simulation: 2 models featured parallel folds that did not enable flow separation in the glottis and 2 models involved a divergent glottis. The influence of the ventricular gap (narrow/wide) is evaluated. An unsteady pressure inlet representing a voicing cycle was applied to the sub-glottal region to mimic the time-varying glottal flow. Intraglottal vortex structures formed downstream of the separation point in a divergent glottis. Their existence caused a higher closing force that was applied onto the vocal folds. A narrow ventricular gap strengthens this effect. Strength of the intraglottal vortices increased with the maximum flow declination rate. Therefore, a more divergent shape of the glottis during glottal closing will be one of the main contributors to the voice quality. |
| Databáze: | OpenAIRE |
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