Numerical geometric acoustics

Samuel F. Potter; Maria Cameron; Ramani Duraiswami

doi:10.1121/1.5147456

Random Rays, Geometric Acoustics, and the Parabolic Wave Equation

10.21236/ada141398 ◽

1984 ◽

Author(s):

Jr Dankel ◽

T.

Keyword(s):

Wave Equation ◽

Geometric Acoustics

Download Full-text

Geometric Acoustics

Ocean Acoustics - Springer Textbooks in Earth Sciences, Geography and Environment ◽

10.1007/978-3-030-35884-6_5 ◽

2020 ◽

pp. 59-70

Author(s):

Anatoly Kistovich ◽

Konstantin Pokazeev ◽

Tatiana Chaplina

Keyword(s):

Geometric Acoustics

Download Full-text

FUNCTIONAL DIFFERENTIAL AND DIFFERENTIAL MODELS OF SYSTEMS WITH ACOUSTICAL FEEDBACK

Bulletin of Bryansk state technical university ◽

10.30987/article_5cb58f516d2bd2.01655840 ◽

2019 ◽

Vol 2019 (4) ◽

pp. 60-67

Author(s):

Валерий Ермолаев ◽

Valeriy Ermolaev ◽

Юрий Кропотов ◽

Yuriy Kropotov ◽

Наталья Холкина ◽

...

Keyword(s):

Sound Propagation ◽

Feedback Mechanism ◽

Warning Systems ◽

Multiple Reflections ◽

Nonlinear Functional ◽

Acoustic Feedback ◽

Feedback Model ◽

Geometric Acoustics ◽

Functional Differential ◽

Analysis Of Stability

The paper reports the investigations of the functional differential and differential models of system with acoustic feedback. The aim of the work is a for-mation, analysis and identification of linear and nonlinear functional differential models of echo, reverberation and acoustic feedback; the analysis of model sensitivity, the analysis of stability of telecommunication systems with the acoustic feedback. There is presented a mechanism of an acoustic feedback mechanism formation. At the analysis of sound propagation in closed rooms with the use of the geometric acoustics method there is obtained a nucleus equation which is approximated by nonnegative functions taking into account a model of reverberation and a model of multiple reflections. The considered procedure of echo formation and reverberation is an element of the feedback model common for warning systems and technological communication. There is investigated a model of acoustic systems with delayed feedback. A diagram of the kernel of a functional differential equation describing a system with feedback is shown. The models of systems with acoustic feedback presented in this work ensure the approximation to reality at that, an account of possibilities of the emergence in channels of non-linear distortion sound propagation are considered to be the next problem.

Download Full-text

Computer Prediction of Insertion Loss Due to a Single Barrier in a Non-Diffuse Empty Enclosed Space

Building Acoustics ◽

10.1177/1351010x9400100203 ◽

1994 ◽

Vol 1 (2) ◽

pp. 125-136 ◽

Cited By ~ 6

Author(s):

S.M. Dance ◽

J.P. Roberts ◽

B.M. Shield

Keyword(s):

Geometric Theory ◽

Computation Time ◽

Extended Version ◽

Complex Environments ◽

Test Space ◽

Computer Prediction ◽

Prediction Program ◽

Geometric Acoustics ◽

Enclosed Space ◽

Barrier Model

This paper describes the development of an efficient barrier model for the prediction of sound distribution in non-diffuse empty enclosed spaces. Diffraction is modelled using an extended version of the Ondet and Barbry computer model, RAYCUB, which is a proven model used to predict sound distribution in empty and fitted non-diffuse enclosed spaces. As RAYCUB is based on geometric acoustics, it is not possible to directly model diffraction around a barrier. Diffraction around barriers is known to cause only localised, frequency dependent effects on sound distribution in acoustically complex environments such as factories. It was intended that a barrier model should impose a minimum of additional computation time on the factory noise prediction program. Three methods of approximating barriers were developed, all based upon a simplified implementation of the geometric theory of diffraction. The barrier models were tested in two configurations of an empty test space. The model REDIR gave more accurate results than the original RAYCUB model, especially at lower frequencies.

Download Full-text