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Combustion Noise

:	Johannes Janicka, Anna Schwarz
:	Anna Schwarz, Johannes Janicka
:	Combustion Noise
:	Springer-Verlag
:	9783642020384
:	1
:	CHF 132.90
:

:	Maschinenbau, Fertigungstechnik
:	English

:	291
:	Wasserzeichen
:	PC/MAC/eReader/Tablet
:	PDF

November, 2008 Anna Schwarz, Johannes Janicka In the last thirty years noise emission has developed into a topic of increasing importance to society and economy. In ?elds such as air, road and rail traf?c, the control of noise emissions and development of associated noise-reduction techno- gies is a central requirement for social acceptance and economical competitiveness. The noise emission of combustion systems is a major part of the task of noise - duction. The following aspects motivate research:• Modern combustion chambers in technical combustion systems with low pol- tion exhausts are 5 - 8 dB louder compared to their predecessors. In the ope- tional state the noise pressure levels achieved can even be 10-15 dB louder.• High capacity torches in the chemical industry are usually placed at ground level because of the reasons of noise emissions instead of being placed at a height suitable for safety and security.• For airplanes the combustion emissions become a more and more important topic. The combustion instability and noise issues are one major obstacle for the introduction of green technologies as lean fuel combustion and premixed burners in aero-engines. The direct and indirect contribution of combustion noise to the overall core noise is still under discussion. However, it is clear that the core noise besides the fan tone will become an important noise source in future aero-engine designs. To further reduce the jet noise, geared ultra high bypass ratio fans are driven by only a few highly loaded turbine stages.

	Foreword	5
	Contents	7
	Preface	12
	1 Numerical RANS/URANS simulation of combustion noise	17
	Introduction	18
	Theoretical Background	18
	RANS/URANS approach	19
	Boundary conditions	20
	RPM-CN approach	20
	Results and Analysis	25
	Indirect combustion noise	25
	Direct combustion noise	35
	Conclusions	42
	References	44
	2 Measurement and Simulation of Combustion Noise emitted from Swirl Burners	48
	Introduction	48
	Theoretical Background	50
	Experimental Setup	50
	Numerical Methods	52
	Results and Analysis	56
	Experiment	56
	Numerical Simulation	64
	Conclusions	74
	References	75
	3 Modeling of noise sources in combustion processes via Large-Eddy Simulation	78
	Introduction	78
	Theoretical Background	79
	Non-Premixed Flames	80
	Partially Premixed Flames	82
	Premixed Flames	83
	LES/CAA Hybrid Approach	85
	Results and Analysis	88
	Open, Non-Premixed Jet Flames	88
	Model Combustor (Partially Premixed Flames)	92
	Tecflam Burner (Premixed Flames)	96
	LES/CAA Coupling	98
	Summary and Conclusions	100
	References	101
	4 Modelling of the Sound Radiation from Flames by means of Acoustic Equivalent Sources	104
	Introduction	104
	Theoretical Background	105
	Hybrid Approach	105
	Equivalent Source Method (ESM)	107
	Boundary Element Method (BEM)	108
	Numerical Simulation of the Flames	110
	Results and Analysis	110
	Numerical Aspects of the Hybrid Method	110
	Location of the Control Surface	117
	Inclusion of Ground Effects	117
	Measurement of the Flame	119
	Results of the Simulation and Comparison with the Measurement	120
	Sound Propagation in a Non-Homogeneous Medium	122
	Conclusions	134
	References	135
	5 Investigation of the Correlation of Entropy Waves and Acoustic Emission in Combustion Chambers	139
	Introduction	140
	Theoretical Background, Test Specification and Data Analysis	140
	Test Specification and Data Analysis	143
	Results and Discussion	148
	Entropy Wave Generator Test Rig (EWG)	148
	Combustor Test Rig	151