게시일: 2011. 9. 19 오전 1:54:50
07.09.2011
1) introduction of material - 01
2) definitions of acoustics and wave - 02
3) Review of undergraduate course
-definition of acoustic wave (Sound) - 03-04
-properties of acoustic wave - 04
-physical quantity of acoustic wave - 04
Magnitude of acoustic wave - 04-05
Spectrum - 05-07
14.09.2011
1) Ch. 5.2 Eqn. of State - 10
-Adiabatic process
-Bulk Modulus, B
-Condensation, s(t)
2) Ch. 5.3 Eqn. of Continuity - 11
3) Ch. 5.4 Eqn. of Momentum - 11-13
-N-S Eqn.
-Euler Eqn.
-Linearize Euler Eqn.
-Wave Eqn. in term of pressure or velocity potential
4) Ch. 5.7 Harmonic Plane Wave - 13-15
-Plane Wave
-1-D Wave Eqn.
-General solution of 1-D Wave Eqn.
-Solution for harmonic motion
-Particle velocity in plane wave
5) Ch. 5.10 Specific Acoustic Impedance - 15-16
-Impedance, resistance and reactance
-Impedance for progressive plane wave
6) Ch. 5.11 Spherical Wave - 16-17
-Acoustic pressure of spherical wave
-Particle velocity of spherical wave
7) Ch. 5.8 Energy Density - 17-19
-Instantaneous energy density
-Intensity
-Energy density and intensity of progressive plane wave
8) Ch. 5.15 Point Source - 19
-Solution of wave Eqn. of point source
21.09.2011
1) Ch. 6.1 ~ .2 Transmission of plane wave through two mediums and wall 22 - 24
-Assume plane wave
-B.C (continuity of pressure and particle velocity at the boundary)
scalar summation : pt = pi + pr at x=0, layer
vector summation : vt = vi + vr at x=0, layer
-Intensity or Energy conservation
2) Ch. 6.3 Transmission through a layers 25-27
-Middle layer can represent various material
3) Ch. 6.4 Oblique Incidence 27-32
-Decomposition of oblique wave into vertical and horizontal wave
-Evanescent wave (oblique wave over critical incident angle for transmitting)
4) Ch. 6.5 - .6 Reflection at the solid surface 32
-impedance: resistance + reactance
28.09.2011
1) Ch. 7 Absorption in Fluids
-additional damping term cause complex wavenumber
05.10.2011
1) Ch. 8.1 Pulsating sphere
-attached file 1,2
2) Ch. 8.4 Simple source
-attached file 3
3) Ch. 8.5 Dipole
-attached file 4
4) Ch. 8.6 Line source
-integration of pulsating sphere along a line
-using compact source assumption ka<<1
-analyze directivity
5) Ch. 8.8 Circular plate
-integration of pulsating sphere on the plate
-using compact source assumption ka<<1
-analyze directivity, far-field definition using concept of decaying behavior
6) Ch. 8.11 Rough estimation of far field
7) Ch. 8.12 Radiation impedance
-mechanical impedance
-radiation impedance, force/vel.
-behavior of resistance and reactance
12.10.2011
1) Ch. 1.9 Acoustic Power
-Concept of acoustic power related to reactance (steady state energy == energy dissipation)
2) Ch. 1.10 Resonance
-Resonance occurs when reactance is '0' or impedance is minimum or mobility, vel./force, is maximum.
-half power point and damping ratio
2) Ch. 9.2 Effects of impedance in the duct
-closed duct
-open duct - without concept of added mass
- with concept of added mass