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Combining analytical models and LES data to determine the transfer function from swirled premixed flames
- Source :
- Combustion and Flame, Combustion and Flame, Elsevier, 2020, 217, pp.222-236. ⟨10.1016/j.combustflame.2020.03.026⟩
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- International audience; A methodology is developed where the acoustic response of a swirl stabilized flame is obtained from a reduced set of simulations. Building upon previous analytical flame transfer functions, a parametrization of the flame response is first proposed, based on six independent physical parameters: a Strouhal number, the mean flame angle with respect to the main flow direction, the vortical structures convection speed, a swirl intensity parameter, a time delay between acoustic and vortical perturbations, as well as a phase shift between bulk and local velocity signals. It is then shown how these parameters can be deduced from steady and unsteady simulations. The methodology is applied to a laboratory scale premixed swirl stabilized flame exhibiting features representative of real aero-engines. In this matter, cold and reactive flow Large Eddy Simulations are first validated by comparing results with reference data from experiments. The high fidelity simulations are seen to be able to capture the flame structure and velocity profiles at different locations while forced flame dynamics for the frequency range of interest also match the experimental data. From the same analytical transfer function model, three methodologies of increasing complexity are presented for the determination of the model parameters, depending on the available data or computational resources. A first estimation of the flame acoustic response is obtained by evaluating parameters from a single stationary flame simulation in conjunction with analytical estimations for the acoustic-convective time delay. Flame dynamics and swirl related parameters can then be determined from a series of robust treatments on pulsed simulations data to improve the model accuracy. It is shown that good qualitative agreement for the flame transfer function can be obtained from a single non-forced simulation while quantitative agreement over the frequency range of interest can be obtained using additional reactive or non-reactive pulsed simulations at one single forcing frequency corresponding to a local gain minimum. The method also naturally handles different perturbation levels.
- Subjects :
- Convection
Mécanique des fluides
General Chemical Engineering
Flame structure
Combustion
Flame transfer function
General Physics and Astronomy
Energy Engineering and Power Technology
Perturbation (astronomy)
02 engineering and technology
Swirling flame
Analytical model
01 natural sciences
Transfer function
Physics::Fluid Dynamics
symbols.namesake
Large Eddy simulation
020401 chemical engineering
0103 physical sciences
Physics::Chemical Physics
0204 chemical engineering
Physics
010304 chemical physics
Large eddy simulation
Experimental data
Flame Transfer Function
General Chemistry
Mechanics
[INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation
Fuel Technology
symbols
Strouhal number
Subjects
Details
- ISSN :
- 00102180
- Volume :
- 217
- Database :
- OpenAIRE
- Journal :
- Combustion and Flame
- Accession number :
- edsair.doi.dedup.....ec5cca0c1a29f9a7b1fc2d7805ea9c92