A review of bias flow liners for acoustic damping in gas turbine combustors

Lahiri, Claus; Bake, Friedrich

doi:10.1016/j.jsv.2017.04.005

Cited by 77 publications

(24 citation statements)

References 180 publications

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“…Temperature effects have mainly been addressed for perforated walls used in gas turbine combustors or in aero-engines combustion chambers. A comprehensive review on combustor liners can be found in Lahiri & Bake's paper [5], which shows that very few studies investigated the influence of temperature on the acoustic impedance of a liner. The effect of temperature for Helmholtz resonators is addressed in several papers for combustion issues [6] [7].…”

Section: Introductionmentioning

confidence: 99%

Experimental Assessment of the Effect of Temperature Gradient Across an Aeroacoustic Liner

Méry

Piot

Sebbane

et al. 2019

Journal of Aircraft

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This study investigates the temperature effect on the impedance of conventional singledegree-of-freedom liners, both without and with grazing flow. Experiments are performed in a controlled environment, with a detailed monitoring of the temperature all along the liner sample. The liner impedance is either derived from the reflection coefficient measured in a normal impedance tube, or is educed with an inverse method from acoustic velocity or wall pressure fields measured in the ONERA grazing flow duct. The influence of the acoustic source level on the temperature of the sample is also addressed, which enlights strong multiphysics coupling between acoustics, flow and thermal phenomena.

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Section: Introductionmentioning

confidence: 99%

Experimental Assessment of the Effect of Temperature Gradient Across an Aeroacoustic Liner

Méry

Piot

Sebbane

et al. 2019

Journal of Aircraft

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“…One can refer to [54] for a detailed investigation on the modeling of orifice impedance for a broad range of geometries and Strouhal numbers. Combining (2) and (3), one obtains the HH resonator impedance:…”

Section: Helmholtz Resonator (H)mentioning

confidence: 99%

“…In order to achieve efficient and clean combustion, there is a dire need for robust control strategies to prevent thermoacoustic instabilities. The use of passive damping devices such as Helmholtz (HH) or Quarter-Wave (QW) dampers is a cost-effective option to prevent these combustion instabilities [1,2]. In the seventies, thermoacoustic instabilities in rocket engines were the topic of several studies, where different acoustic damping enhancement strategies were compared: for example baffles, HH and cylindrical liners in [3], HH, QW and Quincke resonator in [4].…”

Section: Introductionmentioning

confidence: 99%

Stabilization of acoustic modes using Helmholtz and Quarter-Wave resonators tuned at exceptional points

Bourquard

Noiray

2019

Journal of Sound and Vibration

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Acoustic dampers are efficient and cost-effective means for suppressing thermoacoustic instabilities in combustion chambers. However, their design and the choice of their purging air mass flow is a challenging task, when one aims at ensuring thermoacoustic stability after their implementation. In the present experimental and theoretical study, Helmholtz (HH) and Quarter-Wave (QW) dampers are considered. A model for their acoustic impedance is derived and experimentally validated. In a second part, a thermoacoustic instability is mimicked by an electro-acoustic feedback loop in a rectangular cavity, to which the dampers are added. The length of the dampers can be adjusted, so that the system can be studied for tuned and detuned conditions. The stability of the coupled system is investigated experimentally and then analytically, which shows that for tuned dampers, the best stabilization is achieved at the exceptional point. The stabilization capabilities of HH and QW dampers are compared for given damper volume and purge mass flow.

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“…2(b)). For four liner configurations, see Table 1, from experimental studies [1,17] we have computed the near field velocity and pressure profiles and so the effective Rayleigh conductivity. The relative kinematic viscosity ν 0 is computed as quotient of the kinematic viscosity ν = 1.4660 × 10 −5 m 2 /s of air at 15 • C divided by the period δ to the power of four.…”

Section: Numerical Computation Of K Rmentioning

confidence: 99%

“…In Fig. 6, we show the computed normalized specific acoustic impedance ζ for the liner configuration DC006 in comparison with the Melling model (see [18] and [17,Eq. (12)]), that is given an analytic formula.…”

Section: Numerical Computation Of K Rmentioning

confidence: 99%

On impedance conditions for circular multiperforated acoustic liners

et al. 2018

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Background The acoustic damping in gas turbines and aero-engines relies to a great extent on acoustic liners that consists of a cavity and a perforated face sheet. The prediction of the impedance of the liners by direct numerical simulation is nowadays not feasible due to the hundreds to thousands repetitions of tiny holes. We introduce a procedure to numerically obtain the Rayleigh conductivity for acoustic liners for viscous gases at rest, and with it define the acoustic impedance of the perforated sheet. ResultsThe proposed method decouples the effects that are dominant on different scales: (a) viscous and incompressible flow at the scale of one hole, (b) inviscid and incompressible flow at the scale of the hole pattern, and (c) inviscid and compressible flow at the scale of the wave-length. With the method of matched asymptotic expansions we couple the different scales and eventually obtain effective impedance conditions on the macroscopic scale. For this the effective Rayleigh conductivity results by numerical solution of an instationary Stokes problem in frequency domain around one hole with prescribed pressure at infinite distance to the aperture. It depends on hole shape, frequency, mean density and viscosity divided by the area of the periodicity cell. This enables us to estimate dissipation losses and transmission properties, that we compare with acoustic measurements in a duct acoustic test rig with a circular cross-section by DLR Berlin.Conclusions A precise and reasonable definition of an effective Rayleigh conductivity at the scale of one hole is proposed and impedance conditions for the macroscopic pressure or velocity are derived in a systematic procedure. The comparison with experiments show that the derived impedance conditions give a good prediction of the dissipation losses.

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A review of bias flow liners for acoustic damping in gas turbine combustors

Cited by 77 publications

References 180 publications

Experimental Assessment of the Effect of Temperature Gradient Across an Aeroacoustic Liner

Experimental Assessment of the Effect of Temperature Gradient Across an Aeroacoustic Liner

Stabilization of acoustic modes using Helmholtz and Quarter-Wave resonators tuned at exceptional points

On impedance conditions for circular multiperforated acoustic liners

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