CONTROL OF PRESSURE OSCILLATIONS IN COMBUSTION AND FLUID DYNAMICAL SYSTEMS.

These pressure oscillations could be thermo-acoustic in nature (i. e. , sustained by the thermal energy, most often released by combustion), or generated in a variety of circumstances determined by the mechanical and geometrical features of a fluid dynamical system. The basic concepts are discussed including the control of: the flame-driven longitudinal oscillations in a relatively simple, yet typical, combustion system; the organ-pipe type resonance set-up by a loudspeaker in a vertical pipe; and the 'whistler-nozzle' phenomenon set-up in a resonance chamber.