On the time-domain description of conical bores

Agulló, J.; Barjau, Ana; Martínez, Jordi

doi:10.1121/1.402636

Cited by 9 publications

(5 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Again the zero mean flow expressions coincide with those given in Ref. 20. where q p is the amplitude of the pressure impulse.…”

Section: Response Of An Anechoic Cone To An Impulse Input Velocitysupporting

confidence: 59%

“…Table I presents the analytical expressions for these three responses for M 0 0. Their particularizations to M 0 = 0 coincide with the time-domain responses of a conical duct without mean flow obtained by Agulló et al 20 The mean flow does not have any consequences on the qualitative behavior of these responses: The initial impulse is always followed by an exponential wake. For divergent cones, the x coordinates always take positive values, and so the exponential is a decreasing one.…”

Section: Response Of An Anechoic Cone To An Impulse Input Velocitymentioning

confidence: 60%

“…The results include the well-known responses of conical and cylindrical ducts with zero mean flow. 20 Finally Sec. VI introduces future development.…”

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

On the one-dimensional acoustic propagation in conical ducts with stationary mean flow

Barjau

2007

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

This paper proposes a direct time-domain calculation of the time-domain responses of anechoic conical tubes with steady weak mean flow. The starting point is the approximated linear one-dimensional wave equation governing the velocity potential for the case of steady flow with low Mach number. A traveling solution with general space-dependent propagation velocity is then proposed from which the inward and outward pressure and velocity impulse responses can be obtained. The results include the well-known responses of conical and cylindrical ducts with zero mean flow.

show abstract

“…Again the zero mean flow expressions coincide with those given in Ref. 20. where q p is the amplitude of the pressure impulse.…”

Section: Response Of An Anechoic Cone To An Impulse Input Velocitysupporting

confidence: 59%

Section: Response Of An Anechoic Cone To An Impulse Input Velocitymentioning

confidence: 60%

See 1 more Smart Citation

On the one-dimensional acoustic propagation in conical ducts with stationary mean flow

Barjau

2007

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

show abstract

“…However, the continuous-time model of a bore with conical sections has been shown to be stable despite the existence of local unstable elements [23,24]. Although no proof has been found, numerous tests with conical bore systems have indicated that the discrete-time model also remains stable under certain circumstances.…”

Section: Digital Waveguide Modelingmentioning

confidence: 99%

Wave-based Simulation of Wind Instrument Resonators

Walstijn

2007

IEEE Signal Process. Mag.

View full text Add to dashboard Cite

“…This appendix describes the calculation of the reflection and transmission functions of tone-hole discontinuities based upon the use of a time-domain approach adapted from Agulló et al ͑1992͒. Attention is restricted to the case that only a single propagating mode exists in the main air column and the tone hole, which sets upper limits on the maximum diameters of the air column and tone hole for a given signal bandwidth.…”

Section: Introductionmentioning

confidence: 99%

Time-domain simulation of acoustical waveguides with arbitrarily spaced discontinuities

Barjau

Keefe

Cardona

1999

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

The multiconvolution algorithm ͓Martínez et al., J. Acoust. Soc. Am. 84, 1620-1627 ͑1988͔͒ to calculate the impulse response or reflection function of a musical instrument air column has proved to be useful, but it has the limitation that the spacing between discontinuites is constrained to be some multiple of c⌬t ͑for phase velocity c and time step ⌬t͒. This paper presents an improved method, the continuous-time interpolated multiconvolution ͑CTIM͒, where such a limitation has been removed. The response of an air column, modeled as an arbitrary one-dimensional acoustic waveguide constructed using cylindrical or conical bore segments with viscothermal damping and tone-hole discontinuities, is obtained through continuous-time convolutions between analytical reflection and transmission functions and discrete-time pressure signals. The arbitrary spacing between discontinuites is accounted for by interpolation of the discrete-time pressure signals. Many musical instrument air columns possess tone holes that are opened or closed so that tones of different pitches are produced. A time-domain calculation is presented of the acoustic responses of tone-hole discontinuities that may be open or closed. The resulting reflection and transmission functions are well suited for use in the CTIM. INTRODUCTIONThe simulation of the acoustical behavior of wind instruments requires the dynamical description of the main two parts of such systems, the bore and the driver, and their mutual interaction. As the driver is essentially a nonlinear system, it is always described in the time domain through a differential equation. For that reason, even if the bore behaves, under playing conditions, approximately as a linear system, so that its description can be made either in time domain or in frequency domain, it is a time-domain response ͓usually its input impulse response h(t)͔ that is used when studying the bore-to-driver feedback.There are mainly two techniques to calculate h(t): either as the inverse Fourier transform ͑FT͒ of the corresponding frequency response ͓the input impedance Z()͔ or directly in the time domain. The first technique implies all the inconveniences associated with numerical FTs. To overcome these difficulties, Martínez et al. ͑1988a͒ proposed a direct method in the time domain through a numerical multiconvolution process which has proven to be useful. However, that algorithm has a limitation: the time step ⌬t used in the calculation has to be small enough so that each of the spacings between discontinuities along the bore ͑changes in diameter, in taper, open and closed tone holes etc.͒ is an exact multiple of c⌬t ͑where c is the phase velocity of sound in air neglecting dissipation͒. Smith ͑1992͒ worked with a similar idea to simulate wave propagation in strings. There is a brief discussion of a band-limited interpolation method to treat the case where ⌬t is not an exact multiple of c⌬t, but there is no discussion of how this method is generalized to model wave propagation in conical waveguides with discontinuities r...

show abstract

On the time-domain description of conical bores

Cited by 9 publications

References 3 publications

On the one-dimensional acoustic propagation in conical ducts with stationary mean flow

On the one-dimensional acoustic propagation in conical ducts with stationary mean flow

Wave-based Simulation of Wind Instrument Resonators

Time-domain simulation of acoustical waveguides with arbitrarily spaced discontinuities

Contact Info

Product

Resources

About