scholarly journals Coupled interaction between unsteady flame dynamics and acoustic field in a turbulent combustor

2018 ◽  
Vol 28 (11) ◽  
pp. 113111 ◽  
Author(s):  
Vedasri Godavarthi ◽  
Samadhan A. Pawar ◽  
Vishnu R. Unni ◽  
R. I. Sujith ◽  
Nobert Marwan ◽  
...  
Keyword(s):  
Acoustic Field ◽  
Flame Dynamics ◽  
Unsteady Flame

Nonlinear Flame Transfer Function Characteristics in a Swirl-Stabilized Combustor

2006 ◽  
Vol 129 (4) ◽  
pp. 954-961 ◽  
Author(s):  
Benjamin D. Bellows ◽  
Mohan K. Bobba ◽  
Jerry M. Seitzman ◽  
Tim Lieuwen
Keyword(s):  
Nonlinear Response ◽  
Amplitude Dependence ◽  
Acoustic Excitation ◽  
Acoustic Oscillations ◽  
Flame Dynamics ◽  
Large Velocity ◽  
Planar Laser ◽  
Flame Response ◽  
Test Points ◽  
Unsteady Flame

An understanding of the amplitude dependence of the flame response to acoustic excitation is required in order to predict and/or correlate combustion instability amplitudes. This paper describes an experimental investigation of the nonlinear response of a lean, premixed flame to imposed acoustic oscillations. Detailed measurements of the amplitude dependence of the flame response were obtained at approximately 100 test points, corresponding to different flow rates and forcing frequencies. It is observed that the nonlinear flame response can exhibit a variety of behaviors, both in the shape of the response curve and the forcing amplitude at which nonlinearity is first observed. The phase between the flow oscillation and heat release is also seen to have substantial amplitude dependence. The nonlinear flame dynamics appear to be governed by different mechanisms in different frequency and flowrate regimes. These mechanisms were investigated using phase-locked, two- dimensional OH Planar laser-induced fluorescence imaging. From these images, two mechanisms, vortex rollup and unsteady flame liftoff, are identified as important in the saturation of the flame’s response to large velocity oscillations. Both mechanisms appear to reduce the flame’s area and thus its response at these high levels of driving.

Nonlinear Flame Transfer Function Characteristics in a Swirl-Stabilized Combustor

2006 ◽  
Author(s):  
Benjamin D. Bellows ◽  
Mohan K. Bobba ◽  
Jerry M. Seitzman ◽  
Tim Lieuwen
Keyword(s):  
Nonlinear Response ◽  
Amplitude Dependence ◽  
Acoustic Excitation ◽  
Acoustic Oscillations ◽  
Flow Oscillation ◽  
Flame Dynamics ◽  
Large Velocity ◽  
Flame Response ◽  
Test Points ◽  
Unsteady Flame

An understanding of the amplitude dependence of the flame response to acoustic excitation is required in order to predict and/or correlate combustion instability amplitudes. This paper describes an experimental investigation of the nonlinear response of a lean, premixed flame to imposed acoustic oscillations. Detailed measurements of the amplitude dependence of the flame response were obtained at approximately 100 test points, corresponding to different flow rates and forcing frequencies. It is observed that the nonlinear flame response can exhibit a variety of behaviors, both in the shape of the response curve and the forcing amplitude at which nonlinearity is first observed. The phase between the flow oscillation and heat release is also seen to have substantial amplitude dependence. The nonlinear flame dynamics appear to be governed by different mechanisms in different frequency and flowrate regimes. These mechanisms were investigated using phase-locked, two-dimensional OH PLIF imaging. From these images, two mechanisms, vortex rollup and unsteady flame liftoff, are identified as important in the saturation of the flame’s response to large velocity oscillations. Both mechanisms appear to reduce the flame’s area and thus its response at these high levels of driving.

Numerical investigations of unsteady flame propagation in stepped microtubes

RSC Advances ◽  
2015 ◽  
Vol 5 (122) ◽  
pp. 100879-100890 ◽  
Author(s):  
Aditya Prakash Singh ◽  
V. RatnaKishore ◽  
S. Minaev ◽  
Sudarshan Kumar
Keyword(s):  
Boundary Conditions ◽  
Flame Propagation ◽  
Mass Flux ◽  
Crucial Role ◽  
Air Mass ◽  
Numerical Investigations ◽  
Thermal Boundary Conditions ◽  
Flame Dynamics ◽  
Unsteady Flame

Flame dynamics near the contraction is governed by flame stretching. Change in fuel–air mass-flux entering flame plays a crucial role in accelerating the propagating flames at certain thermal boundary conditions as flame reaches the contraction.

APPLICATION OF THE HIGH-RESOLUTION RANS/ILES TECHNOLOGY FOR FLOW SIMULATION AND THE NEARBY ACOUSTIC FIELD OF NEAR-WALL JETS AND MIXING LAYERS

2016 ◽  
Vol 47 (2) ◽  
pp. 159-183 ◽  
Author(s):  
Leonid Aleksandrovich Bendersky ◽  
Dmitriy Aleksandrovich Lyubimov ◽  
Irina Vasilevna Potekhina ◽  
Alena Eduardovna Fedorenko
Keyword(s):  
High Resolution ◽  
Acoustic Field ◽  
Flow Simulation ◽  
Mixing Layers ◽  
Wall Jets ◽  
Near Wall

CALCULATION OF THE INTEGRAL NOISE LEVEL AT A FIELD POINT OF A FREE SUPERSONIC JET OF A ROCKET ENGINE

Akustika ◽  
2020 ◽  
Vol 36 (36) ◽  
pp. 22-24
Author(s):  
Anatoly Kochergin ◽  
Valeeva Ksenia
Keyword(s):  
Acoustic Field ◽  
Noise Level ◽  
Rocket Engine ◽  
Supersonic Jet ◽  
Noise Sources ◽  
Field Point

The paper considers an acoustic field created by a supersonic jet (CES) of a rocket engine freely flowing into flooded space. The acoustic field was presented in the form of a diagram of noise isobars, from which it can be seen that the acoustic field is formed by two effective noise sources: the nearest one, lying at a distance of 5-10 calibers from the nozzle cut and the far one, lying at a distance of 15-30 calibers from the nozzle cut.

Sign in / Sign up

Export Citation Format

Share Document