Prediction of acoustic resonance in tandem cascades

1998 ◽  
Author(s):  
B. Woodley ◽  
N. Peake
Keyword(s):  
Acoustic Resonance ◽  
Tandem Cascades

Assessment of Tongue Position and Laryngeal Height in Two Professional Voice Populations

2020 ◽  
Vol 63 (1) ◽  
pp. 109-124
Author(s):  
Carly Jo Hosbach-Cannon ◽  
Soren Y. Lowell ◽  
Raymond H. Colton ◽  
Richard T. Kelley ◽  
Xue Bao
Keyword(s):  
Vocal Fold ◽  
Vocal Tract ◽  
Current Knowledge ◽  
Acoustic Resonance ◽  
Contact Dynamics ◽  
Voice Disorder ◽  
Music Program ◽  
Tongue Position ◽  
Singer Groups ◽  
Professional Voice

Purpose To advance our current knowledge of singer physiology by using ultrasonography in combination with acoustic measures to compare physiological differences between musical theater (MT) and opera (OP) singers under controlled phonation conditions. Primary objectives addressed in this study were (a) to determine if differences in hyolaryngeal and vocal fold contact dynamics occur between two professional voice populations (MT and OP) during singing tasks and (b) to determine if differences occur between MT and OP singers in oral configuration and associated acoustic resonance during singing tasks. Method Twenty-one singers (10 MT and 11 OP) were included. All participants were currently enrolled in a music program. Experimental procedures consisted of sustained phonation on the vowels /i/ and /ɑ/ during both a low-pitch task and a high-pitch task. Measures of hyolaryngeal elevation, tongue height, and tongue advancement were assessed using ultrasonography. Vocal fold contact dynamics were measured using electroglottography. Simultaneous acoustic recordings were obtained during all ultrasonography procedures for analysis of the first two formant frequencies. Results Significant oral configuration differences, reflected by measures of tongue height and tongue advancement, were seen between groups. Measures of acoustic resonance also showed significant differences between groups during specific tasks. Both singer groups significantly raised their hyoid position when singing high-pitched vowels, but hyoid elevation was not statistically different between groups. Likewise, vocal fold contact dynamics did not significantly differentiate the two singer groups. Conclusions These findings suggest that, under controlled phonation conditions, MT singers alter their oral configuration and achieve differing resultant formants as compared with OP singers. Because singers are at a high risk of developing a voice disorder, understanding how these two groups of singers adjust their vocal tract configuration during their specific singing genre may help to identify risky vocal behavior and provide a basis for prevention of voice disorders.

Acoustic Resonance Classification of Swimbladder-Bearing Fish at Multiple Scales

2013 ◽  
Author(s):  
Timothy K. Stanton ◽  
J. M. Jech ◽  
Roger C. Gauss
Keyword(s):  
Multiple Scales ◽  
Acoustic Resonance

Acoustic Resonance Classification of Swimbladder-Bearing Fish at Multiple Scales

2011 ◽  
Author(s):  
Timothy K. Stanton ◽  
J. M. Jech ◽  
Roger C. Gauss
Keyword(s):  
Multiple Scales ◽  
Acoustic Resonance

Analysis of the Noise Level Generated by Axial Flow Fan Composed of Radial-Bladed Centrifugal Rotor

2014 ◽  
Author(s):  
S. S. Borges ◽  
R. Barbieri ◽  
P. S. B. Zdanski
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Axial Flow ◽  
Acoustic Resonance ◽  
Pressure Level ◽  
Resonance Mode ◽  
Numerical Techniques ◽  
Cooling Systems ◽  
Centrifugal Fans ◽  
Motor Cooling

The objective of this work is to present, by means of experimental, analytical and numerical techniques that sound pressure level generated by radial-bladed centrifugal fans of electric motor cooling systems may be expressed by a logarithmical ratio of the peripheral velocity of rotor, volumetric flow and efficiency of the fan. The proposed methodology proved to be efficient and simple in the prediction of generated noise by radial-bladed centrifugal fans of TEFC motors with accuracy of ± 3 dB. In addition, the acoustic resonance mode of the fan cavity were determined by means of numerical simulations, which its results were validated through experiments using waterfall spectrum.

scholarly journals Sounding out falsified medicines from genuine medicines using Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anas Alfarsi ◽  
Céline Caillet ◽  
Garry Fawbert ◽  
Simon Lawrence ◽  
Jacob Krüse ◽  
...  
Keyword(s):  
Active Ingredient ◽  
Lower Cost ◽  
Principal Component ◽  
Acoustic Resonance ◽  
South East Asia ◽  
Acoustic Signatures ◽  
Falsified Medicines ◽  
Acoustic Phenomenon ◽  
The Eu

AbstractThe trade in falsified medicine has increased significantly and it is estimated that global falsified sales have reached $100 billion in 2020. The EU Falsified Medicines Directive states that falsified medicines do not only reach patients through illegal routes but also via the legal supply chain. Falsified medicines can contain harmful ingredients. They can also contain too little or too much active ingredient or no active ingredient at all. BARDS (Broadband Acoustic Resonance Dissolution Spectroscopy) harnesses an acoustic phenomenon associated with the dissolution of a sample (tablet or powder). The resulting acoustic spectrum is unique and intrinsic to the sample and can be used as an identifier or signature profile. BARDS was evaluated in this study to determine whether a product is falsified or genuine in a rapid manner and at lower cost than many existing technologies. A range of genuine and falsified medicines, including falsified antimalarial tablets from south-east Asia, were tested, and compared to their counterpart genuine products. Significant differences between genuine and falsified doses were found in their acoustic signatures as they disintegrate and dissolve. Principal component analysis was employed to differentiate between the genuine and falsified medicines. This demonstrates that the tablets and capsules included here have intrinsic acoustic signatures which could be used to screen the quality of medicines.

Horizontal extension of acoustic resonance between the ground and the lower thermosphere

2012 ◽  
Vol 75-76 ◽  
pp. 127-132 ◽  
Author(s):  
Mitsuru Matsumura ◽  
Hiroyuki Shinagawa ◽  
Toshihiko Iyemori
Keyword(s):  
Lower Thermosphere ◽  
Acoustic Resonance

Investigations on Aerodynamic Loading Limits of Subsonic Compressor Tandem Cascades: Midspan Flow

2013 ◽  
Author(s):  
Charlotte Hertel ◽  
Christoph Bode ◽  
Dragan Kožulović ◽  
Tim Schneider
Keyword(s):  
Mach Number ◽  
Wind Tunnel ◽  
Numerical Simulations ◽  
Pressure Distribution ◽  
Large Range ◽  
Pressure Rise ◽  
Transition Model ◽  
Diffusion Factor ◽  
Aerodynamic Loading ◽  
Tandem Cascades

An optimized subsonic compressor tandem cascade was investigated experimentally and numerically. Since the design aims at incompressible applications, a low inlet Mach number of 0.175 was used. The experiments were carried out at the low speed cascade wind tunnel at the Technische Universität Braunschweig. For the numerical simulations, the CFD-solver TRACE of DLR Cologne was used, together with a curvature corrected k-ω turbulence model and the γ-Reθ transition model. Besides the incidence variation, the aerodynamic loading has also been varied by contracting endwalls. Results are presented and discussed for different inlet angles and endwall contractions: pressure distribution, loss coefficient, turning, pressure rise, AVDR and Mach number. The comparison of experimental and numerical results is always adequate for a large range of incidence. In addition, a comparison is made to an existing high subsonic tandem cascade and conventional cascades. For the latter the Lieblein diffusion factor has been employed as a measure of aerodynamic loading to complete the Lieblein Chart of McGlumphy [1].

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