TY - JOUR
T1 - A simple multiband approach for solving frequency dependent problems in numerical time domain methods
AU - Sheaffer, Jonathan D.
AU - Fazenda, Bruno M.
AU - Angus, Jamie A.S.
AU - Murphy, Damian T.
PY - 2011
Y1 - 2011
N2 - With the rapid growth of computational power and recent advances in GP-GPU technology, numerical time domain methods are becoming increasingly popular for room acoustics applications due to their accuracy, simplicity and ease of implementation. However, in order to model realistic spaces one should consider boundary conditions and source directivity functions as empirically measured frequency dependent quantities. Previously suggested methods rely on performing time domain convolution or employing recursive filters at the boundaries of the domain. Although shown to be highly accurate, these formulations normally involve complex implementations which not only reduce the attractiveness of using such methods, but may also result in computationally expensive algorithms. In this paper we examine a straightforward approach for solving such frequency dependent problems at the expense of being able to run a single broadband simulation. Using the finite difference time domain (FDTD) method, a number of band-limited frequency independent simulations are initiated in intervals depending on the availability of empirical impedance and directivity data and the desired spectral resolution. Generated impulse responses are filtered according to their respective frequency bandwidths and summed to produce a single frequency dependent impulse response. Intermediate values are automatically interpolated based on the characteristics of the chosen post processing filters. Results are analysed and validated and agreement with theoretical models is shown.
AB - With the rapid growth of computational power and recent advances in GP-GPU technology, numerical time domain methods are becoming increasingly popular for room acoustics applications due to their accuracy, simplicity and ease of implementation. However, in order to model realistic spaces one should consider boundary conditions and source directivity functions as empirically measured frequency dependent quantities. Previously suggested methods rely on performing time domain convolution or employing recursive filters at the boundaries of the domain. Although shown to be highly accurate, these formulations normally involve complex implementations which not only reduce the attractiveness of using such methods, but may also result in computationally expensive algorithms. In this paper we examine a straightforward approach for solving such frequency dependent problems at the expense of being able to run a single broadband simulation. Using the finite difference time domain (FDTD) method, a number of band-limited frequency independent simulations are initiated in intervals depending on the availability of empirical impedance and directivity data and the desired spectral resolution. Generated impulse responses are filtered according to their respective frequency bandwidths and summed to produce a single frequency dependent impulse response. Intermediate values are automatically interpolated based on the characteristics of the chosen post processing filters. Results are analysed and validated and agreement with theoretical models is shown.
UR - http://www.scopus.com/inward/record.url?scp=84866045446&partnerID=8YFLogxK
M3 - Conference article
AN - SCOPUS:84866045446
SN - 2221-3767
SP - 269
EP - 274
JO - Proceedings of Forum Acusticum
JF - Proceedings of Forum Acusticum
T2 - 6th Forum Acusticum 2011
Y2 - 27 June 2011 through 1 July 2011
ER -