FLOW-STRUCTURE-ACOUSTIC INTERACTION IN A HUMAN VOICE MODEL

Stefan Becker
Institute of Process Machinery and System Engineering (iPAT), Friedrich-Alexander University, D-91058 Erlangen, Deutschland

S. Muller
Institut für Geometrie und Praktische Mathematik, RWTH Aachen, Templergraben 55, 52056 Aachen , Germany

S. Kniesburges
Institute of Fluid Mechanics (LSTM), Friedrich-Alexander University Erlangen-Nuremberg Cauerstr. 4, D-91058 Erlangen, Germany

Gerhard Link
Department of Sensor Technology (LSE), Friedrich-Alexander University Erlangen-Nuremberg Paul-Gordan Str. 5, D-91052 Erlangen; ANSYS Germany GmbH, Otterfing, Germany

C. Hahn
Department of Sensor Technology (LSE), Friedrich-Alexander University Erlangen-Nuremberg Paul-Gordan Str. 5, D-91052 Erlangen, Germany

M. Kaltenbacher
Department of Sensor Technology (LSE), Friedrich-Alexander University Erlangen-Nuremberg Paul-Gordan Str. 5, D-91052 Erlangen, Germany

Resumo

For the investigation of the physical processes of the human phonation a fluid-structure-coupled in-vitro model was developed, which constitutes a copy of the human voice. With that model one was able to reproduce manlike process of sound production.
The model made it possible to enforce extensive observations of the flow-induced vocal folds vibrations. Many measurement techniques were applied like flow visualization, Particel Image Velocimetry (PIV) of the time-dependent flow field, unsteady pressure measurement, vibration measurement by a Laser-Scanning-Vibrometer as well as the measurement of the acoustic field. Furthermore correlations were done between the acoustic field and the flow velocity and the movement of the structure.
The results support the existence of the Coanda-effect during phonation. The flow attaches to one vocal fold just past the glottis and forms a spacious vortex behind the vocal folds. That behavior is not linked to one vocal fold and changes stochastically. The sound production is presumed to be produced by oscillations of the vocal folds and the involved oscillating volume flow rate.