Nonlinear Energy Transfer Applied to Data Analysis in Combustion Instability

Eric Jacob, Gary Flandro, Paul Gloyer
2011 47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit   unpublished
The Universal Combustion Device Stability™ (UCDS™) Process is the culmination of more than 40 years of research and provides the means to understand the complex dynamics and processes inside any chemical propulsion system, including rockets, turbojets and scramjets. With UCDS, it is now possible to accurately predict the time history of the pressure oscillation amplitudes during operation. This paper is focused on exploring combustion instability behavior and data analysis. It will start with a
more » ... brief description of the analytical framework at the heart of UCDS. Using the UCDS tools, the nonlinear transfer of energy between different modes of oscillation will be addressed. The difficulties experienced in calculating the linear growth rate, alpha, using linear fitting methods will be shown. Finally, a new way to analyze combustion instability test data by applying the UCDS nonlinear tools in reverse will be shown. As a result, UCDS can be used to either a-priori calculate the stability of a propulsion system, or to reduce experimental data to determine the character of the instability itself.
doi:10.2514/6.2011-5641 fatcat:h5djhkclqvgnrjun4apgckcwk4