1. Combustion Instability Diagnostics Using the Rayleigh Index
- Author
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William E. Anderson, Matthew E. Harvazinski, and Charles L. Merkle
- Subjects
Frequency analysis ,business.product_category ,Materials science ,Phase angle ,Mechanics ,Combustion ,law.invention ,Longitudinal mode ,symbols.namesake ,Rocket ,Normal mode ,law ,symbols ,Combustor ,Rayleigh scattering ,business - Abstract
Numerical simulations of gaseous methane and decomposed hydrogen peroxide in a laboratory rocket combustor were performed in order to determine how to best calculate the Rayleigh index. Calculations using four levels of spatial re nement show the level of re nement necessary to identify the regions of ampli cation and damping is signi cantly coarser than the mesh used for simulation. The Rayleigh index for the rst longitudinal mode is bimodal and shows an isolated area of damping. The two areas of ampli cation are the result of two di erent driving mechanisms. Mode shape, phase angle, and frequency analysis of pressure, velocity, and heat release are presented to validate the combustion modeling approach and interpret the results.
- Published
- 2011
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