Learn about acoustics and sound fields by using the concept of impedance. We will start with the fundamental concept of one-dimensional cases, understand the essentials, and also cover extended topics.
Week 1: Vibration & Waves
- How are time and space related? What about the relation between frequency and wavelength?
- Does the characteristic impedance of medium determine reflection and transmission?
- Do we well see the waves of a string in terms of driving point impedance?
Week 2: Acoustics Wave Equation and Its Basic Physical Measures
(1D acoustic wave equation, Acoustic Intensity and Energy, Units of Sound)
- What are the relations of acoustic pressure, density, and particle velocity?
- How do they make acoustic wave equation?
- Is acoustic wave well analogous with one dimension string wave?
Week 3: Acoustics Wave Equation and Its Basic Physical Measures
(Acoustic Intensity and Energy, Solutions of the Wave equation, Demonstration: hearing system)
- What about the relation between acoustic intensity and energy?
- How does human hearing system measure sound and its characteristics?
- Let us experience the change of sound in level and frequency!
Week 4: Waves on a Flat Surface of Discontinuity
(Normal incidence on a Flat Surface, The Mass Law)
- How mathematically express the boundary conditions at discontinuity?
- How does impedance at discontinuity determine reflection and transmission?
- When can we use mass law?
Week 5: Waves on a Flat Surface of Discontinuity
(Transmission Loss, Snell’s Law, Transmission and Reflection of an Infinite Plate/Finite Structure)
- How different is the transmission loss of a flexible partition compared to the mass law?
- Does the obliqueness of wave play a critical role to determine transmitted and reflected wave?
- What are the roles of partition and fluid loading impedance to transmission loss?
- Yang-Hann Kim - Mechanical Engineering