Trapped compressible air and moving air form a mass-spring acoustic resonator
Evidence
Consider the simple mechanical model of the propagation of sound through some physical medium, shown in Figure 1.1. This shows a simple one-dimensional model of a physical medium, such as air, which we call the golf ball and spring model because it consists of a series of masses, e.g., golf balls, connected together by springs. The golf balls represent the point masses of the molecules in a real material, and the springs represent the intermolecu lar forces between them. If the golf ball at the end is pushed toward the others then the spring linking it to the next golf ball will be compressed and will push at the next golf ball in the line, which will compress the next spring, and so on. — David Howard, Jamie Angus, coustics and Psychoacoustics, 25 (
#expands, via linked claim)
Categorization
- XREF: connects to: An open car window creates a living Helmholtz resonator with strong low-frequency pressure fluctuations; Sound propagation can be modeled as coupled masses and springs — David Howard, Jamie Angus, coustics and Psychoacoustics, 25; Helmholtz resonance is the trapped-air cavity resonance exploited in perforated-panel absorbers (+7 more)
Broader Connections
- Sound propagation can be modeled as coupled masses and springs
#expands(0.95) — David Howard, Jamie Angus, coustics and Psychoacoustics, 25 - Helmholtz resonance is the trapped-air cavity resonance exploited in perforated-panel absorbers
#expands(0.85) - Sound is alternating pressure condensations and rarefactions
#corroborates(0.85) - Resonator pitch scales with gas speed, volume, neck geometry
#expands(0.80) - A closed cylindrical resonator filters sound to odd harmonics
#exemplifies(0.80) - Overblowing a pipe jumps its pitch to the next resonator-supported harmonic
#responds-to(0.80) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1211 - Shape-dependent spring constants make vibration speeds complex in solid objects
#expands(0.75) - Confined geometry modifies acoustic impedance from free-space values
#qualifies(0.75)