摘要:

During the past few years a number of mathematical investigators have directed their efforts toward the solution of differential equations with variable coefficients. These analyses are useful in explaining some of the phenomena which occur in electroacoustic vibrating systems with non‐linear elements. In particular, this mathematics may be used to explain the various phenomena exhibited by a direct radiator loudspeaker with a non‐linear cone suspension system. One of the effects is a jump phenomenon in the response frequency characteristic. Another effect is the production of harmonics and subharmonics.

ISSN:0001-4966    

DOI:10.1121/1.1916255

出版商:Acoustical Society of America    

年代:1944

数据来源: AIP

摘要:

Circular plate with a fluid on one side:The free and forced vibration problems of a clamped plate in an infinite baffle are solved exactly in terms of a set of self‐ and mutualradiation impedances Zmn(ω), associated with the normal modes of a plate vibrating in a vacuum. Computations of these impedances have been made for the lowest four modes over a sufficient range in frequency to solve theforced vibrationproblems that occur in practice as well as thefree vibrationproblem of these modes. The magnitude of the influence of the fluid on the plate is shown to depend only on the frequency of vibration and the non‐dimensional parameterβ = ρ0R/2ρh, whereRis the radius of the plate, 2hthe thickness, and ρ0/ρ the relative density of fluid to plate. Theshiftinresonant frequency, and thechange in shapeof the lowest four modes due to the reaction of the fluid on the plate are computed as a function of β. These changes are found to be important in the range 1<β<8. They are negligible for β<1, the case of radiation into air.

ISSN:0001-4966    

DOI:10.1121/1.1916256

出版商:Acoustical Society of America    

年代:1944

数据来源: AIP

摘要:

The reflection and transmission coefficients due to a change in cross section of a circular tube are determined by calculating the exact pressure distribution in the vicinity of the discontinuity. The fluid medium in the tube is assumed to be ideal in the sense that the pressure distribution satisfies the wave equation. In contrast to the simpler theory which assumes a tube which is small compared to the wave‐length, the following theory is subjected only to the assumption of an ideal fluid.

ISSN:0001-4966    

DOI:10.1121/1.1916257

出版商:Acoustical Society of America    

年代:1944

数据来源: AIP

摘要:

The selective transmission of oblique supersonic waves through a solid plate immersed in water is studied theoretically and experimentally over a frequency range from 1.0 to 3.0 megacycles. Three cases are considered: (1) transmission for angles of incidence less than the critical angles for both dilatational and shear waves; (2) transmission for angles of incidence between the two critical angles; (3) transmission for angles greater than both critical angles. In the frequency region studied good agreement is found between the measured transmission, using the torsion disk method, and the theoretical values. Particular interest attaches to case (3). Study is also made of the supersonic transmission through a stratified medium consisting of a set of solid plates immersed in water. The acoustical Bragg law is investigated and verified experimentally.

ISSN:0001-4966    

DOI:10.1121/1.1916258

出版商:Acoustical Society of America    

年代:1944

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1916259

出版商:Acoustical Society of America    

年代:1944

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1916260

出版商:Acoustical Society of America    

年代:1944

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1916261

出版商:Acoustical Society of America    

年代:1944

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1916262

出版商:Acoustical Society of America    

年代:1944

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1916263

出版商:Acoustical Society of America    

年代:1944

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1916264

出版商:Acoustical Society of America    

年代:1944

数据来源: AIP