Intrinsic thermoacoustic feedback loop in turbulent spray flames

Dynamics and control of premixed combustion systems based on flame transfer and describing functions

“…The previous analysis indicates that there is a growing number of studies examining the complex interplays between these modes, but despite numerous theoretical analysis suggesting the occurrence of ITA modes in real combustors (see for example Ghani et al (2019)), direct experimental evidence of ITA modes are rare and the results are so far limited to the set-up studied by Hoeijmakers et al (2016) with high acoustic losses.…”

Thermoacoustic combustion instability of propane‐oxy‐combustion with CO2dilution: Experimental analysis

“…55 Band-pass filtered measurement, therefore, can only be used without correction to measure relative integral intensity of the intermediate radicals that is proportional to an integral heat release rate. This type of measurement has been carried out for thermoacoustic stability analysis using both OH* 10,16,28,56 and CH* radicals 43,44 in different studies. Using OH* radicals, as heat release markers, is said to be suitable in mixtures that are not rich, 51 and in hydrogen-enriched hydrocarbon fuels, 57 therefore, it has been used in the current study.…”

“…7,8,16 Similar approach to the development of FTF in non-premixed flames can be found in the little literature available on the subject, but with distinct dynamics for heat release fluctuations from premixed flames. Such a model is developed for intrinsic thermoacoustic instability in premixed flames using the low-order network models approach.…”

“…Such a model is developed for intrinsic thermoacoustic instability in premixed flames using the low-order network models approach. 7,8,16 Similar approach to the development of FTF in non-premixed flames can be found in the little literature available on the subject, but with distinct dynamics for heat release fluctuations from premixed flames. 15,17 Magina et al 18 reported that nonpremixed flames response to velocity perturbations is similar to those of premixed flames with differences arising from the dynamics of their respective integrated heat release.…”

“…The thermoacoustic stabilization of the flame corresponds to the M-shaped flame stabilization, which occurs at the equilibrium temperature. 28 Thermoacoustic instability has been extensively studied in air-oxidized, premixed combustion systems 16,[28][29][30][31] as reviewed by Lieuwen. 32 Comparatively, fewer number of studies (mostly using air oxidizer) as regards nonpremixed systems are available despite the fact that, while less pervasive, instability is also existing in non-premixed combustors.…”