Numerical Study of Nonlinear Self-sustained Thermoacoustic Instability in a Swirling Combustor (2020)
Type of ContentConference Contributions - Published
PublisherAmerican Institute of Aeronautics and Astronautics
Self-exited thermoacoustic instability is undesirable in gas turbines and other propulsion systems due to structural vibration, overheating and flame flashback. Such instability is characterized with large-amplitude limit cycle oscillations. It is typically resulting from the dynamic interaction between turbulence flow-flame-acoustics. A better understanding on the interaction, and an alternative design of effective damping/control approach to stabilize combustors are wanted. In this work, 3D numerical simulations are conducted on a swirling combustor to gain insight on the generation of nonlinear swirling flow-flame-coupled thermoacoustic instability. To capture the turbulence flow-combustion-acoustics interaction, the classical turbulence model for swirling flow RNG k-ε and eddy dissipation concept model with 2-steps are applied. The model is validated first with the experimental data available in the literature. Then it is applied to study the effect of swirling number SN. It is found that increasing the SN leads to the amplitude of combustion instability being increased. The dominant frequency is found to shift to a higher value with increased SN. To attenuate the selfexcited thermoacoustic instability, we propose an alternative passive control approach by implementing a heat exchanger at a pre-selected segment of combustor wall; its temperature TH could be varied. Numerical results show that properly setting TH can attenuate the thermoacoustic instability by approximately 20 dB. The present study contributes to developing a platform to simulate nonlinear thermoacoustic instability in a swirling combustor. It also opens up an alternative control means to prevent the onset or attenuate the undesirable limit cycle oscillations.
CitationSun Y, Zhao D (2020). Numerical Study of Nonlinear Self-sustained Thermoacoustic Instability in a Swirling Combustor. AIAA Propulsion and Energy 2020 Forum. AIAA Propulsion and Energy 2020 Forum.
This citation is automatically generated and may be unreliable. Use as a guide only.
ANZSRC Fields of Research40 - Engineering::4017 - Mechanical engineering::401702 - Dynamics, vibration and vibration control
40 - Engineering::4017 - Mechanical engineering::401706 - Numerical modelling and mechanical characterisation
40 - Engineering::4004 - Chemical engineering::400402 - Chemical and thermal processes in energy and combustion
RightsAll rights reserved unless otherwise stated
Showing items related by title, author, creator and subject.
Experimental study of equivalence ratio and fuel flow rate effects on nonlinear thermoacoustic instability in a swirl combustor Zhao H; Li G; Zhao D; Zhang Z; Sun D; Yang W; Li S; Lu Z; Zheng Y (2017)Industrial combustion systems such as power generation gas turbines, rocket motors, furnaces and boilers often face the problem of large-amplitude self-excited pressure oscillations that occur due to the onset of ...
Effect analysis on energy conversion enhancement and NOx emission reduction of ammonia/hydrogen fuelled wavy micro-combustor for micro-thermophotovoltaic application Zhao D; Han L; Li J; Xi, Yunzhi; Gu, Xingpeng; Wang, Ningfei (2021)
Zhao D; Ni S; Wu W; Guan, Y (2020)Unlike hydrocarbon fuel, ammonia (NH3) is an alternative but promising carbon-free renewable fuel. The utilization of NH3 as energy resource can effectively reduce greenhouse gas CO2 emission. Here we explore interdisciplinary ...