ocean acoustic theory - mit opencourseware · 2020. 12. 30. · ocean acoustic theory •...

Ocean Acoustic Theory

• Acoustic Wave Equation

• Integral Transforms

• Helmholtz Equation

• Source in Unbounded and Bounded Media• Reflection and Transmission

• The Ideal Waveguide – Image Method

– Wavenumber Integral

– Normal Modes

• Pekeris Waveguide

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COMPUTATIONAL OCEAN ACOUSTICS

U(t)

r a

Vibrating sphere in an infinite fluid medium.

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6 COMPUTATIONAL OCEAN ACOUSTICS Lecture 3

COMPUTATIONAL OCEAN ACOUSTICS

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COMPUTATIONAL OCEAN ACOUSTICS

Horizontally stratified environment

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COMPUTATIONAL OCEAN ACOUSTICS

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COMPUTATIONAL OCEAN ACOUSTICS

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Mag

nit

ud

e

50 F = 150 Hz

40

30

20

Evanescent Radiating Waves

Waves 10

0 0.2 0.4 0.6 0.8 1.0

Horizontal wavenumber (m-1)

Magnitude of the depth-dependent Green’s function for point source in an

infinite medium. Solid curve: z – z = Ȝ/10; dashed curve: z – zs = 2 Ȝ.s

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13COMPUTATIONAL OCEAN ACOUSTICS Lecture 313.853