William E. Anderson, Steven F. Son, and Stephen D. Heister (Purdue University- School of Aeronautics and Astronautics) To overcome the performance limitation and maintain the benefits of liquid fuels, compatible and energetic additives could be used. However, the effect of increased energy release on combustion instability must be a major concern. The study is a scientific investigation into the combined effects of mean heat distribution and temporal combustion response, and particle damping effects, on liquid rocket engine combustion instabilities. The work seeks to provide fundamental understanding that will enable determinations of the types of energetic additives that can simultaneously improve performance and lead to greater margins from combustion instability. Specifically, we seek to understand how changes in rates of combustion kinetics and energy addition affect combustion instability in an unstable model rocket combustor, how energetic additives change the burning characteristics of fuel drops and how those changes affect the instability characteristics, and how particles can be used to damp out the instability.