Anisotropic minimum dissipation subgrid-scale model in hybrid aeroacoustic simulations of human phonation.

This article deals with large-eddy simulations of three-dimensional incompressible laryngeal flow followed by acoustic simulations of human phonation of five cardinal English vowels, /ɑ, æ, i, o, u/. The flow and aeroacoustic simulations were performed in OpenFOAM and in-house code openCFS, respectively. Given the large variety of scales in the flow and acoustics, the simulation is separated into two steps: (1) computing the flow in the larynx using the finite volume method on a fine moving grid with 2.

Characterization of Supersonic Compressible Fluid Flow Using High-Speed Interferometry.

This paper presents a very effective interference technique for the sensing and researching of compressible fluid flow in a wind tunnel facility. The developed technique is very sensitive and accurate, yet easy to use under conditions typical for aerodynamic labs, and will be used for the nonintrusive investigation of flutter in blade cascades. The interferometer employs a high-speed camera, fiber optics, and available "of-the-shelf" optics and optomechanics.

In vitro experimental investigation of voice production.

The process of human phonation involves a complex interaction between the physical domains of structural dynamics, fluid flow, and acoustic sound production and radiation. Given the high degree of nonlinearity of these processes, even small anatomical or physiological disturbances can significantly affect the voice signal. In the worst cases, patients can lose their voice and hence the normal mode of speech communication.

Comparison of acceleration and impact stress as possible loading factors in phonation: a computer modeling study.

Impact stress (the impact force divided by the contact area of the vocal folds) has been suspected to be the main traumatizing mechanism in voice production, and the main cause of vocal fold nodules. However, there are also other factors, such as the repetitive acceleration and deceleration, which may traumatize the vocal fold tissues. Using an aeroelastic model of voice production, the present study quantifies the acceleration and impact stress values in relation to lung pressure, fundamental frequency (F0) and prephonatory glottal half-width.

Geometry of human vocal folds and glottal channel for mathematical and biomechanical modeling of voice production.

Current models of the vocal folds derive their shape from approximate information rather than from exactly measured data. The objective of this study was to obtain detailed measurements on the geometry of human vocal folds and the glottal channel in phonatory position. A non-destructive casting methodology was developed to capture the vocal fold shape from excised human larynges on both medial and superior surfaces.

Estimation of impact stress using an aeroelastic model of voice production.

The maximum impact stress at the contact of the vocal folds achieved during the oscillation cycle was estimated in phonation using an aeroelastic model of voice production. Relations of impact stress to the lung pressure, fundamental frequency of self-oscillations, prephonatory glottal width, sound pressure level generated at the end of the glottis and vibration amplitude of the vocal folds were studied. Using the fundamental frequency, prephonatory glottal width, lung pressure and airflow rate values found in normal speech, maximum impact stress values of 2-3 kPa were obtained.