A linear acoustic analysis has been conducted to study the combustion instability characteristics of threedimensional baffled combustion chambers. The theoretical formulation is based on a generalized wave equation. Normal mode expansion and spatial averaging techniques are implemented to solve for the acoustic motions in the chamber. Several specific effects of radial and circumferential baffles, and the mechanisms by which baffles eliminate combustion instabilities, are presented. Longitudinalization of transverse waves inside baffle compartments, restriction of velocity fluctuations near the injector face, and reduction in oscillation frequency are studied systematically. The effects of mean flow, temperature nonuniformities, and combustion response on the baffle design and stability behaviors are investigated. Potential destabilizing influences of baffles are found to be the concentration of acoustic pressure at the injector face and of acoustic velocity near the baffle tips, as well as their ensuing interactions with local combustion processes.
All Science Journal Classification (ASJC) codes
- Aerospace Engineering
- Fuel Technology
- Mechanical Engineering
- Space and Planetary Science