Abstract
In aims of decreasing NOx emissions to the atmosphere, the use of lean premixed combustion systems in aeroengines has become a great solution. A downside of this kind of combustion it's their proclivity to thermoacoustics instabilities. In this study a statistical analysis of the pressure time series of an atmospheric pressure, Rijke tube kind, turbulent combustor are studied. We evaluate a mix of methane and air in different proportions and for a certain thermal power, and we go for a higher air flow to a lower one and back. The resulting histograms show us how the pressure is distributed from the stable, to the transitional and to the unstable cases and how the equivalence ratio is a governing parameter for the presence of thermoacoustics instabilities. On how thermoacoustic instabilities have hysteresis properties when we decrease and then increase the air flow in the combustion. Additionally, a study on the pressure signals upstream and downstream of the burner is analysed. The results show that there is a strong coherence between signals downstream the burner towards the liner but very poor one in relation with upstream of the burner.
Original language | English |
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Title of host publication | "Advances in Acoustics, Noise and Vibration - 2021" Proceedings of the 27th International Congress on Sound and Vibration, ICSV 2021 |
Editors | Eleonora Carletti, Malcolm Crocker, Marek Pawelczyk, Jiri Tuma |
Publisher | Silesian University Press |
ISBN (Electronic) | 9788378807995 |
Publication status | Published - 2021 |
Event | 27th International Congress on Sound and Vibration, ICSV 2021 - Virtual, Online Duration: 11 Jul 2021 → 16 Jul 2021 Conference number: 27 |
Conference
Conference | 27th International Congress on Sound and Vibration, ICSV 2021 |
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Abbreviated title | ICSV 2021 |
City | Virtual, Online |
Period | 11/07/21 → 16/07/21 |
Keywords
- Combustion noise
- Experimental
- Histograms
- Pearson correlation
- Self-excitation
- Thermoacoustic instabilities
- NLA