Back to Search
Start Over
On resonant triad interactions of acoustic–gravity waves
- Source :
- Kadri
- Publication Year :
- 2015
- Publisher :
- Cambridge University Press (CUP), 2015.
-
Abstract
- The propagation of wave disturbances in water of uniform depth is discussed, accounting for both gravity and compressibility effects. In the linear theory, free-surface (gravity) waves are virtually decoupled from acoustic (compression) waves, because the speed of sound in water far exceeds the maximum phase speed of gravity waves. However, these two types of wave motion could exchange energy via resonant triad nonlinear interactions. This scenario is analysed for triads comprising a long-crested acoustic mode and two oppositely propagating subharmonic gravity waves. Owing to the disparity of the gravity and acoustic length scales, the interaction time scale is longer than that of a standard resonant triad, and the appropriate amplitude evolution equations, apart from the usual quadratic interaction terms, also involve certain cubic terms. Nevertheless, it is still possible for monochromatic wavetrains to form finely tuned triads, such that nearly all the energy initially in the gravity waves is transferred to the acoustic mode. This coupling mechanism, however, is far less effective for locally confined wavepackets.<br />MIT-Technion Fellowship
- Subjects :
- Physics
010504 meteorology & atmospheric sciences
Mechanical Engineering
Mechanics
Acoustic wave
Internal wave
Condensed Matter Physics
Ion acoustic wave
01 natural sciences
010305 fluids & plasmas
General Relativity and Quantum Cosmology
symbols.namesake
Classical mechanics
Mechanics of Materials
0103 physical sciences
symbols
Gravity wave
Rayleigh wave
Dispersion (water waves)
Mechanical wave
Longitudinal wave
0105 earth and related environmental sciences
Subjects
Details
- ISSN :
- 14697645 and 00221120
- Volume :
- 788
- Database :
- OpenAIRE
- Journal :
- Journal of Fluid Mechanics
- Accession number :
- edsair.doi.dedup.....02381ab232e1ac23df0ad14378d3685f