ISSN:0001-4966    

DOI:10.1121/1.1915793

出版商:Acoustical Society of America    

年代:1935

数据来源: AIP

摘要:

Sound analysis by a single band pass filter requires a considerable time, which is inversely proportional to the square of the frequency discrimination. Analyzers consisting of multiple resonators are cumbersome and do not cover a continuous frequency band. The paper describes a new method based on the dispersing properties of a diffraction grating analogous to those used in optical analysis and equivalent to an infinite number of resonators. The sound frequencies are modulated by a 40‐kilocycle carrier, projected by a ribbon loudspeaker and reflected by a curved grating three meters long. The frequency discrimination thus attained equals that of a 125‐cycle band selector; the theoretical speed of analysis approaches 0.01 second, making it possible to obtain “moving pictures” of continuously changing sound spectra.

ISSN:0001-4966    

DOI:10.1121/1.1915794

出版商:Acoustical Society of America    

年代:1935

数据来源: AIP

摘要:

Data are presented giving the measured acoustic reactance and resistance for a number of circular orifices varying in diameter from 1 cm down to 0.034 cm, and for a rectangular orifice 1.9 cm×0.075 cm. The measurements were made for various particle velocities, the corresponding Reynolds numbers varying from 0.7 to 3000, roughly. The reactance is found substantially independent of the particle velocity; a formula for computing it is given. The resistance approaches a constant value as the velocity is sufficiently decreased; formulae for computing this “low velocity” resistance are given. At larger velocities the resistance increases with the velocity. This is discussed from the standpoint of a loss of kinetic energy of flow, acting besides viscosity and turbulence.

ISSN:0001-4966    

DOI:10.1121/1.1915795

出版商:Acoustical Society of America    

年代:1935

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915796

出版商:Acoustical Society of America    

年代:1935

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915797

出版商:Acoustical Society of America    

年代:1935

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915798

出版商:Acoustical Society of America    

年代:1935

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915799

出版商:Acoustical Society of America    

年代:1935

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915800

出版商:Acoustical Society of America    

年代:1935

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915801

出版商:Acoustical Society of America    

年代:1935

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915802

出版商:Acoustical Society of America    

年代:1935

数据来源: AIP