Introduction to Aeroacoustics and Self-Sustained Oscillations of Internal Flows

摘要: After a review of basic equations fluid dynamics, the Aeroacoustic analogy Lighthill is derived. This describes sound field generated by complex flow from point view listener immerged in uniform stagnant fluid. The concept monopole, dipole and quadrupole are introduced. scaling power subsonic free jet explained, providing an example use integral formulation analogy. influence Doppler Effect on radiation moving source explained. By considering noise bubbly liquid, we illustrate importance choice aeroacoustic variable provides some insight into usefulness alternative formulations, such as Vortex Sound Theory. energy corrolary Howe based Theory appears to be most suitable theory understand various aspects self-sustained oscillation due coupling vortex shedding with acoustic standing waves resonator. approach used analyse convective losses at open pipe termination, human whistling, instabilities diffusers, pulsations systems deep closed side branches whistling corrugated pipes.