摘要:

The coupling between the finite‐element and boundary‐element methods is presented in which part of the coupling surface is a solid–fluid interface and part a fluid–fluid interface. The equations are derived for the case of quadratic elements on the finite‐element side (atilacode) and surfaces of uniform velocity on the boundary‐element side (chiefcode). The accuracy of the method is illustrated by two examples: the scattering of plane waves from a fluid sphere and from a spherical Helmholtz resonator.

ISSN:0001-4966    

DOI:10.1121/1.410568

出版商:Acoustical Society of America    

年代:1994

数据来源: AIP

摘要:

Turbulent pressure fluctuations were measured with piezoelectric pressure transducers which were covered with a 0.125‐in.‐thick elastomer window on a buoyant vehicle. Model predictions (i.e., corrections) were made to account for the turbulent pressure attenuation through the elastomeric coating and spatial averaging effects of a finite transducer. The corrected results were compared with classic turbulent spectral densities measured by others and found to be in good agreement.

ISSN:0001-4966    

DOI:10.1121/1.410569

出版商:Acoustical Society of America    

年代:1994

数据来源: AIP

摘要:

This communication concerns the nature of the mechanisms by which the binaural auditory system combines, across frequency, interaural timing information. New observations are presented which indicate that the integration of such information isnotdue to a simple averaging across frequency. Instead, the new observations underscore the importance of the monaural time structure of the stimuli. These observations reinforce our postulation of a mechanism which relies on temporally coincident activity across frequency channels that monitor the same interaural delays.

ISSN:0001-4966    

DOI:10.1121/1.410570

出版商:Acoustical Society of America    

年代:1994

数据来源: AIP

摘要:

The ultrasonic absorption and velocity at 21 MHz and also the shear viscosity were measured for poly (vinyl alcohol) and water solutions. The concentrations of poly (vinyl alcohol) by weight that were used were 1%, 3%, 5%, 9%. Measurements were made at 25°, 30°, 35°, 40°, and 45 °C. It was found that α/f2decreased with increasing temperature and increased with increasing concentration. The wave velocity increased with both temperature and concentration. The shear viscosity was observed to decrease with temperature and increase with concentration.

ISSN:0001-4966    

DOI:10.1121/1.411309

出版商:Acoustical Society of America    

年代:1994

数据来源: AIP

摘要:

A simple matched‐field tracking algorithm is proposed for transit detection in shallow water. Because shallow water bathymetry involves strong variations in depth and sediment properties, it is proposed that the reference functions contain only the direct and surface reflected sound paths which can be quickly calculated. A realistic simulation indicates that the algorithm may have useful performance.

ISSN:0001-4966    

DOI:10.1121/1.410571

出版商:Acoustical Society of America    

年代:1994

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.410575

出版商:Acoustical Society of America    

年代:1994

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.411455

出版商:Acoustical Society of America    

年代:1994

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.411405

出版商:Acoustical Society of America    

年代:1994

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.410583

出版商:Acoustical Society of America    

年代:1994

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.410588

出版商:Acoustical Society of America    

年代:1994

数据来源: AIP