Learners might have learned the basic concepts of the acoustics from the ‘Introduction to Acoustics (Part 1).’ Now it is time to apply to the real situation and develop their own acoustical application. Learners will analyze the radiation, scattering, and diffraction phenomenon with the Kirchhoff –Helmholtz Equation. Then learners will design their own reverberation room or ducts that fulfill the condition they have set up.
Week 1. Radiation – Breathing & Trembling Sphere Problem
- What happens if we have a certain discontinuity that is a function of three spatial variables (e.g. x,y,z for Cartesian coordinate)?
- What are the radiation characteristics of a breathing sphere, which is assumed to vibrate omni-directionally with equal magnitude?
- What is the difference between a breathing sphere and a trembling sphere, which vibrates in a certain direction with a uniform velocity?
Week 2. Radiation – Baffled Piston & Finite Vibrating Plate Problem
- How can we generate sound? By the fluctuation of fluid particles or the vibration of structures? How are they related?
- How can we understand the radiation of a finite vibrating plate? Can we assume this plate as numerous vibrating pistons?
Week 3. Scattering & Diffraction / Kirchhoff-Helmholtz Equation
- How can we express the wave propagation when it is reflected due to the presence of discontinuities in space?
- How can we explain the circumstances under which we can hear sound but cannot see the sound source?
- What is the relation between the wavelength and the diffraction?
Week 4. Wave Propagation in Space / Reverberation Period and its Design Application
- If there are different types of impedance distribution in space, how can we explain the propagation characteristics?
- How can we acoustically define ‘large’ or ‘small’ space’? Is it related to the frequency?
- Is there any measure that can represent the characteristics of the space?
Week 5. Wave
Propagation in Space / Duct Acoustics
- How can we express the sound field that is neither fully diffuse field nor only a direct field?
- When the size of the space is small relative to wavelength, what happens to the propagation of sound?
- When the length of one direction is significantly greater than the cross-sectional direction of the space, how does the wave propagate with respect to its wavelength?