Analysis of combustion noise of a turbulent premixed slot jet flame

Schlimpert, Stephan; Koh, Seong Ryong; Pausch, Konrad; Meinke, Matthias; Schröder, Wolfgang

doi:10.1016/j.combustflame.2016.08.001

Cited by 27 publications

(14 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Accordingly, the sound pressure distributions of unconfined flames show similar behavior and do not exhibit pronounced peaks. This is confirmed by systematic measurements for unconfined jet flames [10,11] and slit flames [12]. The sound pressure spectra measured therein are of broadband nature with a peak frequency that scales linearly with the flame length and with the inverse of the injection velocity.…”

supporting

confidence: 68%

Measurement and Simulation of Combustion Noise and Dynamics of a Confined Swirl Flame

Merk¹,

Polifke²,

Gaudron³

et al. 2018

AIAA Journal

View full text Add to dashboard Cite

The combustion noise produced by a confined, turbulent, premixed swirl burner is predicted with large-eddy simulation of compressible, reacting flow. Characteristics-based state-space boundary conditions are coupled to the large-eddy simulation to impose precisely and independently from each other magnitude and phase of the acoustic reflection coefficients at the boundaries of the computational domain. The coupling approach proves to be accurate and flexible in regard to the estimation of sound pressure spectra in a confined swirl combustor for different operating conditions. The predicted sound pressure levels and its spectral distributions are compared to measurements. Excellent qualitative and quantitative agreement is achieved not only for a stable configuration but also for configurations that exhibit a thermoacoustic instability. This indicates that the flow and flame dynamics are reasonably well reproduced by the simulations.

show abstract

supporting

confidence: 68%

Measurement and Simulation of Combustion Noise and Dynamics of a Confined Swirl Flame

Merk¹,

Polifke²,

Gaudron³

et al. 2018

AIAA Journal

View full text Add to dashboard Cite

show abstract

“…Out of a few studies on premixed flames, Silva et al [2013] highlighted the importance of grid resolution in LES in terms of the prediction of heat release rate fluctuations and consequently the produced sound. In another study, Schlimpert et al [2017] performed LES of noise generation by a premixed slot jet flame using a hybrid approach. In their simulation, the level-set approach was used to describe the motion of the flame with the so-called G-equation.…”

Section: Les Studiesmentioning

confidence: 99%

Sound generation by turbulent premixed flames

et al. 2018

View full text Add to dashboard Cite

This paper presents a numerical study of the sound generated by turbulent, premixed flames. Direct numerical simulations (DNS) of two round jet flames with equivalence ratios of 0.7 and 1.0 are first carried out. Single-step chemistry is employed to reduce the computational cost, and care is taken to resolve both the near and far fields and to avoid noise reflections at the outflow boundaries. Several significant features of these two flames are noted. These include the monopolar nature of the sound from both flames, the stoichiometric flame being significantly louder than the lean flame, the observed frequency of peak acoustic spectral amplitude being consistent with prior experimental studies and the importance of so-called ‘flame annihilation’ events as acoustic sources. A simple model that relates these observed annihilation events to the far-field sound is then proposed, demonstrating a surprisingly high degree of correlation with the far-field sound from the DNS. This model is consistent with earlier works that view a premixed turbulent flame as a distribution of acoustic sources, and provides a physical explanation for the well-known monopolar content of the sound radiated by premixed turbulent flames.

show abstract

“…[14][15][16] Another source of indirect combustion noise due to compositional inhomogeneities which cause the transfer of chemical potential energy into acoustic energy in the accelerating flow has recently been identified in literature. [17][18][19] The spectral shape of direct combustion noise from open flames has frequently been studied, e.g., experimentally in Kotake and Takamoto 20 and Rajaram and Lieuwen 21 at varying fuels, flow parameters, and burner geometries, numerically in Schlimpert et al, 22 and empirically in Tam et al 23 Tam et al 23 analyzed experimental data from the literature and derived an empirical law for the heat release spectrum. Schlimpert et al 22 studied the heat release spectra and the acoustic response to heat release fluctuations in a low, medium, and high frequency range.…”

Section: Introductionmentioning

confidence: 99%

“…[17][18][19] The spectral shape of direct combustion noise from open flames has frequently been studied, e.g., experimentally in Kotake and Takamoto 20 and Rajaram and Lieuwen 21 at varying fuels, flow parameters, and burner geometries, numerically in Schlimpert et al, 22 and empirically in Tam et al 23 Tam et al 23 analyzed experimental data from the literature and derived an empirical law for the heat release spectrum. Schlimpert et al 22 studied the heat release spectra and the acoustic response to heat release fluctuations in a low, medium, and high frequency range. In agreement with Rajaram et al, 21 their results suggest that the acoustic response to heat release fluctuations follows a constant trend of approximately aSt 2 for lower frequencies, i.e., St 20, and bSt 0 in the high frequency region, i.e., St > 20, where St ¼ xL f =v is the flame Strouhal number which is a function of the angular frequency x, the mean streamwise velocity v, and the mean flame height L f .…”

Section: Introductionmentioning

confidence: 99%

Impact of burner plenum acoustics on the sound emission of a turbulent lean premixed open flame

Herff

Pausch

Nawroth

et al. 2020

International Journal of Spray and Combustion Dynamics

View full text Add to dashboard Cite

The acoustic field of a turbulent lean cpremixed open flame is numerically investigated by a hybrid method solving the Navier-Stokes equations in a large-eddy simulation formulation and the acoustic perturbation equations. The interaction of acoustic modes of a burner plenum and the turbulent flame is analyzed with respect to the sound emission of the flame. It is investigated if a simplified computation yields a good broadband agreement of the sound pressure spectrum with experimental measurements. The results of two numerical setups, i.e., the first configuration consists of the burner plus the plenum geometry while in the second configuration the plenum is neglected, which is often done in technical applications due to computational efficiency reasons, are compared with experimental findings. It can be concluded that the plenum has a pronounced impact on the dynamics and combustion noise of the open flame. To be more precise, the comparative juxtaposition of the numerical and experimental results shows a good agreement only for the full burner-plenum computation since the interaction of the acoustic quarter-wave modes of the burner plenum with the jet flow has to be captured. The interaction of these quarter-wave modes with the flow is analyzed and the acoustic response to heat release fluctuations of the flame of the full burner-plenum computation is compared to that of the simplified burner computation, in which the plenum acoustics is neglected. Due to the excitation by the plenum acoustics, the jet flow of the full burner plenum contains higher turbulent kinetic energy and the flame is excited at several additional frequencies which result in distinct peaks in the acoustic spectrum and a higher overall sound pressure level.

show abstract

Analysis of combustion noise of a turbulent premixed slot jet flame

Cited by 27 publications

References 40 publications

Measurement and Simulation of Combustion Noise and Dynamics of a Confined Swirl Flame

Measurement and Simulation of Combustion Noise and Dynamics of a Confined Swirl Flame

Sound generation by turbulent premixed flames

Impact of burner plenum acoustics on the sound emission of a turbulent lean premixed open flame

Contact Info

Product

Resources

About