Study on Combustion Dynamic Characteristics of Oxygen-Rich Preburners

The present study experimentally investigates dynamic characteristics of combustion occurring at highly excessive oxygen environments. Combustion experiments burning kerosene and liquid oxygen were conducted at chamber pressures of 5–20 MPa, and their dynamic pressure fluctuations were measured. The systematic analysis of pressure data confirms that the combustion is sound, with root-mean-square values below 3% of chamber pressures, except a single condition of a chamber pressure of 8.9 MPa, at which low-frequency bulk mode combustion instability at 78 Hz spontaneously occurred. The application of nonlinear time-series analysis shows that certain hidden nonlinear behaviors can be identified, implying that they may be used for the assessment of a combustion stability margin.