Numerical investigation of mode competition and cooperation on the combustion instability in a non-premixed combustor

Liu, Yuanzhe; Liu, Peijin; Wang, Zhuopu; Xu, Guanyu; Jin, Bingning

doi:10.1016/j.actaastro.2022.05.001

Cited by 13 publications

(3 citation statements)

References 40 publications

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“…Extensive studies have been conducted in the last half century targeting on the instabilities of the SRMs, using experimental, theoretical, and numerical methods [5][6][7][8][9][10]. According to these studies, there are many driving and damping factors that together determine the stability of a motor.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation on the Mechanism of Solid Rocket Motor Instability Induced by Differences between On-Ground and In-Flight Conditions

Wang,

Li,

et al. 2024

Aerospace

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A solid rocket motor (SRM) with a high aspect ratio that performs normally during ground tests may experience instability during flight. To address this issue, this study employs the pulse triggering method and the numerical approach of two-way fluid–structure interaction to investigate the mechanisms behind the SRM instability resulting from distinctions between on-ground and in-flight conditions. The results indicate that the main distinctions between the on-ground and in-flight conditions for SRMs are the strong constraints during the ground test, as well as aerodynamic forces and aerodynamic heating during flight. The strong constraints in the ground test effectively suppress structural vibrations by limiting displacements. In flight conditions, the aerodynamic heating reduces the strength of the SRM casing and aerodynamic forces provide sustained energy input for structural vibrations during flight. The mechanism for the ground/flight differences that induce SRM instability is that the structural natural frequencies are reduced by aerodynamic heating and the first-order acoustic frequency increased by the propellant regression approach reaches the resonance condition. Therefore, an instability factor Φ is proposed to represent the resonance relationship between the structural natural modes and the acoustic mode of SRMs. Furthermore, the closer the frequency of the aerodynamic forces is to the resonance frequency of the acoustic-structure coupling, the more pronounced the SRM instability.

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Section: Introductionmentioning

confidence: 99%

Numerical Investigation on the Mechanism of Solid Rocket Motor Instability Induced by Differences between On-Ground and In-Flight Conditions

Wang,

Li,

et al. 2024

Aerospace

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“…Energy conversion from heat to sound is desired in thermoacoustic engines [1][2][3], because there are no or fewer moving parts and non-exotic materials involved. When this occurs in most modern combustion equipment with high energy densities (such as in liquid/solid rocket engines [4][5][6], aero-engines [7][8][9], or land-based gas turbines [10][11][12]), intense thermoacoustic oscillations may occur, which pose a significant risk due to destructive damage [13][14][15]. This may include, structural vibration fatigue, overloaded heating to the combustor walls, and even explosion.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation on the Stochastically Forced Rijke-Type Supercritical Thermoacoustic Systems

Zhang¹,

WANG²,

Li³

et al. 2023

Preprint

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Intense thermoacoustic oscillations may lead to severe deterioration due to the induced intolerable damage to combustors. A better understanding of unstable behaviors is important to prevent or suppress these oscillations. Active thermoacoustic coupling in practical combustors is caused primarily by two approaches: inherent turbulent fluctuations and the flame response to acoustic waves. Turbulent fluctuations are generally characterized by random noise. This paper experimentally expands on previous analytic studies regarding the influence of colored disturbances on the thermoacoustic response near the supercritical bifurcation point. Therein, a laboratory-scale Rijke-type thermoacoustic system is established, and both supercritical and subcritical bifurcations are observed. Then, Ornstein–Uhlenbeck (OU)-type external colored noise is introduced near the supercritical bifurcation point, and the effects of the corresponding correlation time τc and noise intensity D are studied. The experimental results show that these variables of the colored noise significantly influence the dynamics of thermoacoustic oscillations in terms of the most probable amplitude, autocorrelation, and correlation time. A resonance-like behavior is observed as the noise intensity or the autocorrelation time of the colored noise is continuously varied, which means that the coherent resonance occurs in the thermoacoustic system. Finally, when the system is configured closer to the stability boundary, the extent of the coherence motion is intensified in the stochastic system response. Meanwhile, the Signal to Noise Ratios (SNRs) of the colored-noise-induced response are found to become more distinguished, the optimal colored noise intensity decreases, and the optimal autocorrelation time increases. This provides valuable guidance to predict the onset of thermoacoustic instabilities.

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“…Energy conversion from heat to sound is desired in thermoacoustic engines [1,2], because there are no moving parts or fewer moving parts and non-exotic materials involved. When this occurs in most modern combustion equipment with high energy densities (such as in liquid/solid rocket engines [3,4], aero-engines [5][6][7], or land-based gas turbines [8][9][10]), intense thermoacoustic oscillations may occur, which pose a significant risk due to destructive damage [11][12][13]. This may include structural vibration fatigue, overloaded heating to the combustor walls, and even explosion.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of Stochastically Forced Rijke-Type Supercritical Thermoacoustic Systems

Zhang,

Wang,

et al. 2023

Energies

View full text Add to dashboard Cite

Intense thermoacoustic oscillations may lead to severe deterioration due to the induced intolerable damage to combustors. A better understanding of unstable behaviors is important to prevent or suppress these oscillations. Active thermoacoustic coupling in practical combustors is caused primarily by two approaches: inherent turbulent fluctuations and the flame response to acoustic waves. Turbulent fluctuations are generally characterized by random noise. This paper experimentally expands on previous analytic studies regarding the influence of colored disturbances on the thermoacoustic response near the supercritical bifurcation point. Therein, a laboratory-scale Rijke-type thermoacoustic system is established, and both supercritical and subcritical bifurcations are observed. Then, Ornstein–Uhlenbeck (OU)-type external colored noise is introduced near the supercritical bifurcation point, and the effects of the corresponding correlation time τc and noise intensity D are studied. The experimental results show that these variables of the colored noise significantly influence the dynamics of thermoacoustic oscillations in terms of the most probable amplitude and autocorrelation properties. A resonance-like behavior is observed as the noise intensity or the autocorrelation time of the colored noise is continuously varied, which means that the coherent resonance occurs in the thermoacoustic system. Finally, when the system is configured closer to the stability boundary, the extent of the coherence motion is intensified in the stochastic system response. Meanwhile, the signal-to-noise ratios (SNRs) of the colored-noise-induced response are found to become more distinguished, the optimal colored noise intensity decreases, and the optimal autocorrelation time increases. These findings provide valuable guidance to predict the onset of thermoacoustic instabilities.

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Numerical investigation of mode competition and cooperation on the combustion instability in a non-premixed combustor

Cited by 13 publications

References 40 publications

Numerical Investigation on the Mechanism of Solid Rocket Motor Instability Induced by Differences between On-Ground and In-Flight Conditions

Numerical Investigation on the Mechanism of Solid Rocket Motor Instability Induced by Differences between On-Ground and In-Flight Conditions

Experimental Investigation on the Stochastically Forced Rijke-Type Supercritical Thermoacoustic Systems

Experimental Investigation of Stochastically Forced Rijke-Type Supercritical Thermoacoustic Systems

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