http://www.cnr.it/ontology/cnr/individuo/prodotto/ID42566
Spontaneous Oscillations in Lean Premixed Combustors: CFD simulation (Articolo in rivista)
- Type
- Label
- Spontaneous Oscillations in Lean Premixed Combustors: CFD simulation (Articolo in rivista) (literal)
- Anno
- 2007-01-01T00:00:00+01:00 (literal)
- Alternative label
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
- V. Di Sarli, F.S. Marra and A. Di Benedetto (literal)
- Pagina inizio
- Pagina fine
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
- Rivista
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroFascicolo
- Note
- ISI Web of Science (WOS) (literal)
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
- Titolo
- Spontaneous Oscillations in Lean Premixed Combustors: CFD simulation (literal)
- Abstract
- Lean premixed (LPM) combustors allow reduction of NOx emissions,
but they often experience instabilities that are detrimental for engines structural
integrity and performances. Most of the works dealing with LPM combustors
oscillations address the occurrence of dynamic regimes to system instabilities,
i.e., to the coupling between variations of heat release from the flame and acoustic
modes of the combustion chamber. However, premixed flames may be prone to
intrinsic instabilities: the flame itself oscillates, independently from the coupling
with combustor acoustics. In the present article, RANS-based CFD simulations
were performed to study the dynamic behavior of an LPM combustor by varying
the length of the inlect duct, the inlet gas velocity and fuel equivalence ratio, and
the combustor wall temperature. The model results show that the LPM combustor
oscillations may be different in nature: they may originate from system
instabilities or from the propagation to the whole combustor of the flame intrinsic
oscillations due to heat losses (thermo-kinetic oscillations). Furthermore, it is
found that whatever the driving mechanism (system or flame instability) a whole
acoustic mode is excited and, accordingly, Rayleigh's criterion is always verified.
Conversely, the widely used re-statement of Rayleigh's criterion based on the
time-delay approach is verified only for the oscillations originated by system
instability, while it fails with the thermo-kinetic oscillations. A way to discern
between the different mechanisms exciting the oscillations in an LPM combustor
is then suggested. (literal)
- Prodotto di
- Autore CNR
Incoming links:
- Prodotto
- Autore CNR di
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi