Analysis of the interaction of thermoacoustic modes with a Green’s function approach
| Autor: | Alessandra Bigongiari, Maria A. Heckl |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
020209 energy
lcsh:Mechanical engineering and machinery lcsh:Motor vehicles. Aeronautics. Astronautics General Physics and Astronomy Energy Engineering and Power Technology 02 engineering and technology Computational fluid dynamics 01 natural sciences 010305 fluids & plasmas symbols.namesake 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Applied mathematics lcsh:TJ1-1570 Network model Physics business.industry Function (mathematics) Thermoacoustic instability Nonlinear system Green's function Automotive Engineering symbols Non normality lcsh:TL1-4050 business |
| Zdroj: | International Journal of Spray and Combustion Dynamics, Vol 10 (2018) |
| ISSN: | 1756-8285 1756-8277 |
| Popis: | In this paper, we will present a fast prediction tool based on a one-dimensional Green's function approach that can be used to bypass numerically expensive computational fluid dynamics simulations. The Green’s function approach has the advantage of providing a clear picture of the physics behind the generation and evolution of combustion instabilities. In addition, the method allows us to perform a modal analysis; single acoustic modes can be treated in isolation or in combination with other modes. In this article, we will investigate the role of higher-order modes in determining the stability of the system. We will initially produce the stability maps for the first and second mode separately. Then the time history of the perturbation will be computed, where both the modes are present. The flame will be modelled by a generic Flame Describing Function, i.e. by an amplitude-dependent Flame Transfer Function. The time-history calculations show the evolution of the two modes resulting from an initial perturbation; both transient and limit-cycle oscillations are revealed. Our study represents a first step towards the modelling of nonlinearity and non-normality in combustion processes. |
| Databáze: | OpenAIRE |
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