Effect of inlet flow turbulence on the combustion instability in a premixed backward-facing step combustor

Nagarajan, Baladandayuthapani; Baraiya, Nikhil A.; Chakravarthy, Satyanarayanan R.

doi:10.1016/j.proci.2018.06.143

Cited by 18 publications

(1 citation statement)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[22][23][24] Consequently, fluid properties and chemical reaction kinetics become the two main factors that have a significant impact on thermoacoustic instability. [25][26][27] The properties of the inlet fluid have an important influence on the combustion instability, such as turbulence intensity, 28 fluid dynamical vortex, 29 and inlet velocity. 30 Besides, equivalence ratio has also been proved to have a significant influence on combustion instability.…”

Section: Introductionmentioning

confidence: 99%

Analysis of separating acoustics from the thermoacoustic system of methane combustion based on Reynolds-averaged Navier-Stokes and linearized Navier-Stokes equations

Shen

Liu

2023

Journal of Low Frequency Noise, Vibration and Active Control

View full text Add to dashboard Cite

A model coupling Reynolds-averaged Navier-Stokes (RANS) method and linearized Navier-Stokes equations (LNSEs) was established in order to investigate the acoustic excitation and attenuation effect from a coupling perspective of time–space–frequency under various flow velocities and mass fractions of methane. Results show that the energy distribution of acoustic modes under high-frequency acoustic excitation is more uniform. The amplitude of the acoustic oscillation at a multiple coupling physical field is 10,000 times higher than that at simple flow field. The case when [Formula: see text] = 0.8 owns the largest percentage of energy conversion from fundamental to high-frequency signals, the largest percentage of transmitted waves from the combustion chamber system to outside and the strongest non-linear effect. When [Formula: see text] rises, the amplitude of oscillations at points and the attenuation effect of high-frequency signals along the axial are enhanced. At the case of Uin = 15 m/s, the amplitude of harmonics is reduced by 18% compared with other cases, while the proportion of the high-frequency harmonic increases, proving the non-linearity cannot be neglected in this case. As velocity rises, the energy conversion from fundamental to high-frequency signals enhances; while closer to the outlet position, the more complex the oscillation signal is. Model-shapes analysis shows that a case of [Formula: see text] = 0.8 owns the largest amplitude of the second harmonic at downstream of the burner, while the amplitude of the harmonics rapidly increases at Uin = 15 m/s at the end of the burner, which further indicates that the energy conversion of low-frequency signals to high-frequency signals occurs mainly in the middle and downstream regions.

show abstract

Section: Introductionmentioning

confidence: 99%

Analysis of separating acoustics from the thermoacoustic system of methane combustion based on Reynolds-averaged Navier-Stokes and linearized Navier-Stokes equations

Shen

Liu

2023

Journal of Low Frequency Noise, Vibration and Active Control

View full text Add to dashboard Cite

show abstract

Macrostructure and NO_x emission evolution characteristics of lean‐premixed flames under combustion instability

Tao

Zhou

2020

Asia-Pacific J Chem Eng

View full text Add to dashboard Cite

Effects of combustion instability on flame macrostructures and NO x emissions were conducted experimentally in a model gas turbine combustor. Two variables of the CH 4 flame were investigated-the flow rate and the equivalence ratio. Results indicate that flame macrostructure changes when the equivalence ratio increases from 0.50 to 1.00, the average total length of flame front firstly decreases from 105 to 75 mm, and then increases to 110 mm. While the average length of flame root decreases from 25 to 5 mm. The appearance of the flame front evolves from a "M" shape to a reversed "V" shape, but the appearance of the flame root changes from elongated V shape to a flatted V shape. The envelop diagram of different combustion instability signifies that there are mode shifting of flame-acoustic interactions in the combustion chamber. Under instability conditions, the temperature and velocity distribution of the flame front or flame root affects the NO x emissions. Along the radial direction, the peak temperature in the inner recirculation region and the outer recirculation region drops. This article explored the dynamic characteristics of lean-premixed flames under combustion instability, which could be instructive to the designing of stable and clean combustors in industrial gas turbines.

show abstract

Experimental Investigation of Combustion Instability in Syngas Turbulent Combustor

Baraiya

Chakravarthy

2021

Lecture Notes in Mechanical Engineering

View full text Add to dashboard Cite

Effect of inlet flow turbulence on the combustion instability in a premixed backward-facing step combustor

Cited by 18 publications

References 12 publications

Analysis of separating acoustics from the thermoacoustic system of methane combustion based on Reynolds-averaged Navier-Stokes and linearized Navier-Stokes equations

Analysis of separating acoustics from the thermoacoustic system of methane combustion based on Reynolds-averaged Navier-Stokes and linearized Navier-Stokes equations

Macrostructure and NO_x emission evolution characteristics of lean‐premixed flames under combustion instability

Experimental Investigation of Combustion Instability in Syngas Turbulent Combustor

Contact Info

Product

Resources

About

Effect of inlet flow turbulence on the combustion instability in a premixed backward-facing step combustor

Cited by 18 publications

References 12 publications

Analysis of separating acoustics from the thermoacoustic system of methane combustion based on Reynolds-averaged Navier-Stokes and linearized Navier-Stokes equations

Analysis of separating acoustics from the thermoacoustic system of methane combustion based on Reynolds-averaged Navier-Stokes and linearized Navier-Stokes equations

Macrostructure and NOx emission evolution characteristics of lean‐premixed flames under combustion instability

Experimental Investigation of Combustion Instability in Syngas Turbulent Combustor

Contact Info

Product

Resources

About

Macrostructure and NO_x emission evolution characteristics of lean‐premixed flames under combustion instability