Theoretical and experimental investigation of thermoacoustics transfer function

Zhang, Zhiguo; Zhao, Dan; Dobriyal, Ritvik; Zheng, Youqu; Yang, Wenming

doi:10.1016/j.apenergy.2015.04.026

Cited by 26 publications

(7 citation statements)

References 44 publications

(64 reference statements)

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“…Thus it is important to gain insight on the onset of thermoacoustic instability [12,13,2] and to develop mitigation/-control approaches. Over last few decades, thermoacoustic instability has been intensively studied [14][15][16][17][18][19][20]. Generally, linear modal analysis is conducted via calculating the eigenfrequencies of thermoacoustic systems [3].…”

Section: Introductionmentioning

confidence: 99%

Transient growth of acoustical energy associated with mitigating thermoacoustic oscillations

Zhao

Yang

et al. 2016

Applied Energy

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Section: Introductionmentioning

confidence: 99%

Transient growth of acoustical energy associated with mitigating thermoacoustic oscillations

Zhao

Yang

et al. 2016

Applied Energy

Self Cite

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“…In Sect.2, the frequency-domain model of a flow duct with the structure-modified Helmholtz resonator used is proposed by solving linearized NS (Navier-Stokes) governing equations. [23][24][25][26][27][28][29] Validation is conducted first to justify the proposed model by considering with the conventional Helmholtz resonator (i.e., no rigid baffle applied at the neck) via comparing with theoretical and experimental results available in the literature. The model is then applied to study the transmission loss performance of the proposed Helmholtz resonators with the rigid baffle implemented at the neck.…”

Section: Introductionmentioning

confidence: 99%

Numerical optimizing noise damping performances of Helmholtz resonators with a rigid baffle implemented at neck in presence of a grazing flow

Guan

2022

Journal of Low Frequency Noise, Vibration and Active Control

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As an applicable noise attenuator, Helmholtz resonator is mainly used to dampen acoustic noise at low- and medium-frequency ranges. It is typically implemented in combustion-engines and gas turbines to dampen thermoacoustic instabilities. However, it has a narrow effective frequency range and does not work effectively at off-design conditions. In this work, we consider a modified structured Helmholtz resonator (HR) at its neck by applying a rigid baffle in order to maximize its’ noise damping effect and to broaden its frequency bands. The resonator is attached to a cylindrical duct/pipe in presence of a mean flow (grazing flow), aiming to simulate the practical engines flow configuration. For this, a two-dimensional frequency domain numerical model is developed by using COMSOL V5.3. The numerical simulations are carried out by solving the linearized Navier–Stokes equation in frequency domain with low computational cost and time. In order to obtain an optimum design in terms of the maximum noise damping performances, 10 new different configurations/designs are proposed. The effects of 1) the single baffle attached to the upstream or downstream sidewall of the neck ends, that is, Design A, B, C, and D or double baffles, that is, Design E, F, G, and H), 2) the baffle implementation location, 3) the length of the rigid baffle, and 4) the grazing flow low Mach number are evaluated and compared. It is found that Design C is associated with improved TL by 50% and decreased resonant frequency by 20% comparing with the conventional HR. The present preliminary study shows that Design C is the better design. Further experimental and optimization researches are needed to sheds light on the optimum design of a Helmholtz resonator with neck structure being modified, as there is a low Mach number grazing flow.

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“…While the acoustic response to these instabilities is typically linear, the flame's heat release response can be highly non-linear, particularly at high forcing amplitudes, and hence the overall device can be expected to behave like a coupled non-linear dynamical system [6,44]. Several experimental and numerical investigations have been conducted to determine the FDF [24,25,[44][45][46][47][48][49][50][51]. Lieuwen [45] investigated the response of premixed flames to inlet velocity oscillations, and observed that, as flow perturbations increased, the amplitude of the flame response was lower than that predicted by the linear transfer function.…”

Section: Introductionmentioning

confidence: 99%

Investigating the effect of local addition of hydrogen to acoustically excited ethylene and methane flames

Hussain

Talibi

Balachandran

2019

International Journal of Hydrogen Energy

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While lean combustion in gas turbines is known to reduce NOx, it makes combustors more prone to thermo-acoustic instabilities, which can lead to deterioration in engine performance. The work presented in this study investigates the effectiveness of secondary injection of hydrogen to imperfectly premixed methane and ethylene flames in reducing heat release oscillations. Both acoustically forced and unforced flames were studied, and simultaneous OH and H atom PLIF (planar laser induced fluorescence) was conducted. The tests were carried out on a laboratory scale bluff-body combustor with a central V-shaped bluff body. Two-microphone method was used to estimate velocity perturbations from pressure measurements, flame boundary images were captured using high speed Mie scattering, while global heat release fluctuations were determined from OH* chemiluminescence. The results showed that hydrogen addition considerably reduced heat release oscillations for both methane and ethylene flames at all the forcing frequencies tested, with the exception of methane flames forced at 315 Hz, where oscillations increased with hydrogen addition. The addition of hydrogen reduced the extent of flame roll-up for both methane and ethylene flames, however, this reduction was larger for methane flames. NOx exhaust emissions were observed to increase with hydrogen addition for both methane and ethylene flames, with absolute NOx concentrations higher for ethylene flames, due to higher flame temperatures.

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Theoretical and experimental investigation of thermoacoustics transfer function

Cited by 26 publications

References 44 publications

Transient growth of acoustical energy associated with mitigating thermoacoustic oscillations

Transient growth of acoustical energy associated with mitigating thermoacoustic oscillations

Numerical optimizing noise damping performances of Helmholtz resonators with a rigid baffle implemented at neck in presence of a grazing flow

Investigating the effect of local addition of hydrogen to acoustically excited ethylene and methane flames

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