A spectral model for the sound pressure from turbulent premixed combustion

Hirsch, Christoph; Wäsle, J.; Winkler, A.; Sattelmayer, Thomas

doi:10.1016/j.proci.2006.07.154

Cited by 59 publications

(52 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this correlation was not investigated sufficiently despite many empirical length scale of v cor proposed in previous studies (e.g. laminar flame thickness δ L (Bragg, 1963), turbulence integral length scale (Strahle, 1971), turbulent flame-brush thickness (Wäsle et al, 2005;Hirsch et al, 2007)), and it is still unclear about the appropriate length scale for v cor . Recently, Swaminathan et al (2011,a) modelled this correlation through direct numerical simulation (DNS) (Rutland and Cant, 1994;Nada et al, 2004Nada et al, , 2005 and laser diagnostics (Balachandran et al, 2005) data of turbulent premixed flames, and estimated the correlation volume as δ 3 L /8 by assuming isotropic correlation, where δ L is the laminar flame thermal thickness.…”

Section: Introductionmentioning

confidence: 99%

On the Space-Time Correlation of Heat Release Rate in Turbulent Premixed Flames

Liu

2015

Combustion Science and Technology

View full text Add to dashboard Cite

The spectral characteristics of combustion noise is dictated by the temporal correlation of the heat release rate fluctuation. This paper investigates the two-point space-time correlation of heat release rate fluctuations by analysing recent direct numerical simulation (DNS) data of turbulent premixed flames. The results show that this correlation decays rapidly in both space and time due to the abrupt fluctuation of the heat release rate. The two-point space-time correlation can be modelled by Gaussian-type functions including the streamwise direction with strong convection. A flat low-frequency dependence is observed for the spectrum of the correlation function, which will allow the modelling of the spectral peak and the low-frequency spectral slope of combustion noise when multiplying the term ω 2 (ω is the angular frequency). This exploratory work shows the potential of this correlation function for capturing the spectral shape of combustion noise.

show abstract

Section: Introductionmentioning

confidence: 99%

On the Space-Time Correlation of Heat Release Rate in Turbulent Premixed Flames

Liu

2015

Combustion Science and Technology

View full text Add to dashboard Cite

show abstract

“…5,7,6 This deficiency is improved in this paper after applying corrections to the model. The input of mean quantities for this model can be obtained from either measurement 5,6 or CFD simulation. 7 In the work reported here, it is obtained from Reynolds-averaged Navier-Stokes (RANS) calculations for the combustor flow field.…”

mentioning

confidence: 99%

“…In the model, a local wave number model spectrum of heat release rate fluctuation is mapped to a frequency spectrum required to calculate the sound pressure spectrum. The spectral model was validated experimentally on premixed swirling jet flames 5,6 with underpredictions observed at low frequencies. 5,7,6 This deficiency is improved in this paper after applying corrections to the model.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Prediction of Combustion Noise for an Aeroengine Combustor

Liu

Dowling²,

Swaminathan³

et al. 2014

Journal of Propulsion and Power

View full text Add to dashboard Cite

Combustion noise may become an important noise source for lean-burn gas turbine engines, and this noise is usually associated with highly unsteady flames. This work aims to compute the broadband combustion noise spectrum for a realistic aeroengine combustor, and to compare with available measured noise data on a demonstrator aeroengine.A low-order linear network model is applied to a demonstrator engine combustor to obtain the transfer function that relates to unsteadiness in the rate of heat release, acoustic, entropic and vortical fluctuations. A spectral model is used for the heat release rate fluctuation, which is the source of the noise. The mean flow of the aeroengine combustor required as input data to this spectral model is obtained from RANS simulations. The computed acoustic field for a low-medium power setting indicates that the models used in this study capture the main characteristics of the broadband spectral shape of combustion noise. Reasonable agreement with the measured spectral level is achieved.

show abstract

“…It has been recently noted [5,6] that the two-point 17 spatial correlation of the rate of change of fluctuating heat release rate, 18 and hence the associated correlation volume v cor and its length scale, is 19 crucial to predicting combustion noise. In previous studies, different length 20 scales have been suggested to estimate v cor empirically, ranging from the 21 laminar flame thickness δ L [12], turbulence integral length scale Λ [13] to the 22 turbulent flame-brush thickness [14,15] or a combination of them. However, 23 the two-point correlation of heat release rate has not received sufficient 24 attention primarily owing to the lack of availability of reliable numerical 25 or experimental data for the fluctuating heat release rate required to directly 26 investigate the correlation length scale.…”

mentioning

confidence: 99%