Time-domain simulation of directive sources in 3-D digital waveguide mesh-based acoustical models

Digital waveguide mesh (DWM) models offer a simple, accurate, time-domain, numerical solution of the wave equation. A specific case where such accurate and computationally simple solutions are needed is the acoustical modeling of open or closed volumes. It is possible to model 3-D propagation of waves in enclosures such as rooms using DWM models. Generally, idealized omnidirectional sources are used for obtaining the impulse response in the DWM. However, real-life sound sources are never completely isotropic, causing wavefronts with directional properties. This paper presents two methods to simulate analytical and empirical directivities in 3-D DWM models in the far-field. The first method is based on the direct excitation of the mesh with the velocity component of the directional source and is used to simulate analytical sources. The second method is based on the weighting of velocity components generated by an omnidirectional source at different octave-bands and is used to simulate sources with frequency-dependent empirical directivity functions. A simple interpolation method for obtaining a closed-form description of the directivity function from incomplete directivity data is also proposed. Simulation results are presented for two sources in an acoustical model of a rectangular room.


On the accuracy of first-order numerical derivatives in multidimensional digital waveguide mesh topologies
Hacıhabiboğlu, Hüseyin; Günel Kılıç, Banu (2008-01-01)
Digital waveguide mesh (DWM) models are numerical solvers for the wave equation in N-dimensions. They are used for obtaining the traveling-wave solution in practical acoustical modeling applications. Although unstructured meshes can be used with DWMs, regular mesh topologies are traditionally used due to their implementation simplicity. This letter discusses the accuracy of first-order approximations to numerical derivatives on more general unstructured mesh topologies. The results are applied to structured...
Simulation of Directional Microphones in Digital Waveguide Mesh-Based Models of Room Acoustics
Hacıhabiboğlu, Hüseyin; Günel Kılıç, Banu (2010-02-01)
Digital waveguide mesh (DWM) models are time-domain numerical methods providing computationally simple solutions for wave propagation problems. They have been used in various acoustical modeling and audio synthesis applications including synthesis of musical instrument sounds and speech, and modeling of room acoustics. A successful model of room acoustics should be able to account for source and receiver directivity. Methods for the simulation of directional sources in DWM models were previously proposed. T...
Time-domain mapping of electromagnetic ray movement inside anisotropic spherical resonator
Biber, A; Golick, A; Tomak, Mehmet (2002-09-01)
This paper presents the analytical proof of "Time-Domain Mapping Method" for the spherical resonator made up of uniaxial crystal. In this way, the main types of caustics inside the spherical resonator made up of uniaxial crystal, which were investigated numerically before, are confirmed analytically. It is engraved that the problem of the ray flow inside the spherical resonator can be reduced to the problem of the ray flow inside metal cavity shaped as spheroid.
BULUTAY, C; PRASAD, S (1993-06-01)
Three-dimensional condensed asymmetrical node, variable grid, transmission-line matrix (TLM) method has been used in analyzing several millimeter waveguides on anisotropic substrates. The dispersion characteristics of image guides together with field and energy confinement properties at millimeter-wave frequencies have been investigated. Edge coupled microstrip line on a uniaxial substrate is analyzed for the even and odd mode dispersion characteristics. Finally the same analysis is repeated for bilateral f...
Moving mesh discontinuous Galerkin methods for PDEs with traveling waves
UZUNCA, MURAT; Karasözen, Bülent; Kucukseyhan, T. (2017-01-01)
In this paper, a moving mesh discontinuous Galerkin (dG) method is developed for nonlinear partial differential equations (PDEs) with traveling wave solutions. The moving mesh strategy for one dimensional PDEs is based on the rezoning approach which decouples the solution of the PDE from the moving mesh equation. We show that the dG moving mesh method is able to resolve sharp wave fronts and wave speeds accurately for the optimal, arc-length and curvature monitor functions. Numerical results reveal the effi...
Citation Formats
H. Hacıhabiboğlu and B. Günel Kılıç, “Time-domain simulation of directive sources in 3-D digital waveguide mesh-based acoustical models,” IEEE TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING, pp. 934–946, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30586.