Flow pattern- and forces-susceptibility to small attack angles for a rectangular cylinder

Zhou, Lei; Zhu, Qingchi; Tse, K.T.; Ning, Xizhan; Ai, Yifeng; Zhang, Hongfu

doi:10.1016/j.oceaneng.2024.117376

Cited by 16 publications

(2 citation statements)

References 43 publications

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“…With the increasing performance requirements of combustion chambers and increasingly stringent emission regulations [1][2][3][4], gas turbine combustion chambers are required to operate at high temperature and high pressure [5][6][7][8][9], which usually leads to the occurrence of combustion instability [10][11][12][13][14][15][16][17]. The combustion instability phenomenon will be accompanied by pressure pulsation and exothermic pulsation in the flow field inside the combustion chamber [18][19][20][21], which leads to vibration of the combustion chamber components and affects the safe operation of the engine [22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Impact of Oxygen Content on Flame Dynamics in a Non-Premixed Gas Turbine Model Combustor

Chen,

Huang,

Wang

et al. 2024

JMSE

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In this study, large eddy simulation (LES) was used to investigate the dynamic characteristics of diffusion flames in a swirl combustion chamber at an oxygen content of 11–23 wt% and temperature of 770 K. The proper orthogonal decomposition (POD) method was employed to obtain flame dynamic modes. The results indicate that oxygen content has a significant impact on the downstream flow and flame combustion characteristics of the swirl combustion chamber. With oxygen content increasing, the size of the recirculation zone is reduced, and the flame field fluctuations are intensified. The pressure and heat release fluctuations under different oxygen contents were analyzed using frequency spectrum analysis. Finally, the flame modes were analyzed using the POD method, and it was found that the coherent structures are asymmetric relative to the local coordinate system. At an oxygen content of 11 wt%, they exhibit larger coherent structures, while at an oxygen content of 23 wt%, they exhibit numerous turbulent structures.

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Section: Introductionmentioning

confidence: 99%

Impact of Oxygen Content on Flame Dynamics in a Non-Premixed Gas Turbine Model Combustor

Chen,

Huang,

Wang

et al. 2024

JMSE

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“…Low oxygen content is detrimental to stable combustion [2][3][4][5], significantly reducing the combustion reaction rate and flame propagation speed in the afterburner [6][7][8]. Moreover, the incoming flow velocity in the afterburner is exceptionally high, and minor perturbations can potentially lead to combustion instability [9][10][11][12][13]. Combustion instability manifests as periodic pressure and temperature pulsations [14][15][16], posing a risk of severe mechanical vibration and localized overheating of the aero-engine.…”

Section: Introductionmentioning

confidence: 99%

Exploring Vortex–Flame Interactions and Combustion Dynamics in Bluff Body-Stabilized Diffusion Flames: Effects of Incoming Flow Velocity and Oxygen Content

Chen,

Zhao,

Wang

et al. 2024

Processes

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An afterburner encounters two primary features: high incoming flow velocity and low oxygen concentration in the incoming airflow, which pose substantial challenges and contribute significantly to the deterioration of combustion performance. In order to research the influence of oxygen content on the dynamic combustion characteristics of the afterburner under various inlet velocities, the effect of oxygen content (14–23%) on the field structure of reacting bluff body flow, flame morphology, temperature pulsation, and pressure pulsation of the afterburner at different incoming flow velocities (0.1–0.2 Ma) was investigated in this study by using a large eddy simulation method. The results show that two different instability features, BVK instability and KH instability, are observed in the separated shear layer and wake, and are influenced by changes in the O2 mass fraction and Mach number. The oxygen content and velocity affected the oscillation amplitude of the downstream flow. As the O2 mass fraction decreases, the flame oscillation amplitude increases, the OH concentration in the combustion chamber decreases, and the flame temperature decreases. Additionally, the amplitude of the temperature pulsation in the bluff body flame was primarily influenced by the temperature intensity of the flame and BVK instability. Moreover, the pressure pulsation is predominantly affected by the dynamic characteristics of the flow field behind the bluff body. When the BVK instability dominated, the primary frequency of the pressure pulsation aligned with that of the temperature pulsation. Conversely, under the dominance of the KH instability, the temperature pulsation did not exhibit a distinct main frequency. At present, the influence of oxygen content and incoming flow rate on the combustion performance of the combustion chamber is not clear. The study of the effect of oxygen content on the combustion characteristics of the combustion chamber at different incoming flow rates provides a reference for improving the performance of the combustion chamber and enhancing the combustion stability.

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Vibration-based multiphase flow identification by deep learning for the vertical section of subsea pipelines

Qiao,

Guo,

Huang

et al. 2024

Applied Ocean Research

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Flow pattern- and forces-susceptibility to small attack angles for a rectangular cylinder

Cited by 16 publications

References 43 publications

Impact of Oxygen Content on Flame Dynamics in a Non-Premixed Gas Turbine Model Combustor

Impact of Oxygen Content on Flame Dynamics in a Non-Premixed Gas Turbine Model Combustor

Exploring Vortex–Flame Interactions and Combustion Dynamics in Bluff Body-Stabilized Diffusion Flames: Effects of Incoming Flow Velocity and Oxygen Content

Vibration-based multiphase flow identification by deep learning for the vertical section of subsea pipelines

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