Measurements and Calculations of Spectral Radiation Intensities for Turbulent Non-Premixed and Partially Premixed Flames

2003 ◽  
Vol 125 (4) ◽  
pp. 678-686 ◽  
Author(s):  
Yuan Zheng ◽  
R. S. Barlow ◽  
Jay P. Gore

Spectral radiation intensities leaving diametric and chord-like paths for six non-sooting flames were measured using an infrared array spectrometer. The spectral radiation intensities were also computed using the mean property approach and a time and space series simulation approach. Turbulence/radiation interactions (TRI) in these flames were investigated by comparing the two sets of computations to the experimental data. The effects of TRI are significant for regions away from the flame axis. The new data and findings are of value in the evaluation of radiation models, which are increasingly used in turbulent combustion calculations.

2003 ◽  
Author(s):  
Yuan Zheng ◽  
Jay P. Gore

A recently developed technique called time and space series analysis was used to calculate the mean and fluctuating spectral radiation intensities leaving diametric and chord-like paths in turbulent partially premixed flames. A standard flame (Flame D) from Sandia Workshop on Turbulent Non-premixed Flames was selected to allow an evaluation of the radiation calculations at least at the single point statistics level. Measurements of spectral radiation intensities using a fast infrared array spectrometer provide an evaluation of the computations and also allow estimation of the length and time scales of scalar fluctuations, which appear as model parameters in the time and space series analysis modeling.


AIAA Journal ◽  
2002 ◽  
Vol 40 (11) ◽  
pp. 2289-2297 ◽  
Author(s):  
Hongshe Xue ◽  
Suresh K. Aggarwal

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Ping Wang ◽  
Qian Yu ◽  
Prashant Shrotriya ◽  
Mingmin Chen

In the present work, the fluctuations of equivalence ratio in the PRECCINSTA combustor are investigated via large eddy simulations (LES). Four isothermal flow cases with different combinations of global equivalence ratios (0.7 or 0.83) and grids (1.2 or 1.8 million cells) are simulated to study the mixing process of air with methane, which is injected into the inlet channel through small holes. It is shown that the fluctuations of equivalence ratio are very large, and their ranges are [0.4, 1.3] and [0.3, 1.2] for cases 0.83 and 0.7, respectively. For simulating turbulent partially premixed flames in this burner with the well-known dynamically thickened flame (DTF) combustion model, a suitable multistep reaction mechanism should be chosen aforehand. To do that, laminar premixed flames of 15 different equivalence ratios are calculated using three different methane/air reaction mechanisms: 2S_CH4_BFER, 2sCM2 reduced mechanisms and GRI-Mech 3.0 detailed reaction mechanism. The variations of flame temperature, flame speed and thickness of the laminar flames with the equivalence ratios are compared in detail. It is demonstrated that the applicative equivalence ratio range for the 2S_CH4_BFER mechanism is [0.5, 1.3], which is larger than that of the 2sCM2 mechanism [0.5, 1.2]. Therefore, it is recommended to use the 2S_CH4_BFER scheme to simulate the partially premixed flames in the PRECCINSTA combustion chamber.


2018 ◽  
Vol 22 (5) ◽  
pp. 862-882 ◽  
Author(s):  
Zhi X. Chen ◽  
N. Anh Khoa Doan ◽  
Shaohong Ruan ◽  
Ivan Langella ◽  
N. Swaminathan

2004 ◽  
Vol 16 (8) ◽  
pp. 2963-2974 ◽  
Author(s):  
Xiao Qin ◽  
Ishwar K. Puri ◽  
Suresh K. Aggarwal ◽  
Viswanath R. Katta

Author(s):  
Alexander Maltsev ◽  
Amsini Sadiki ◽  
Johannes Janicka

To improve the numerical prediction of partially premixed flames occurring in gas turbine combustors the extension of the well-known Bray-Moss-Libby model for premixed combustion is presented. The model modification based on the algebraic closure for a mean chemical source term is coupled to the mixing transport model providing variable equivalence ratio distinguishing partially premixed flames. Finite rate chemistry is incorporated by means of ILDM model solving transport equations for two reaction progress variables conditioned on the flame front. Multivariate presumed PDF model is used for the turbulence chemistry interaction treatment. Turbulence models of two levels of complexity are applied in order to investigate the influence of non-gradient turbulent transport phenomenon. Redistribution terms in second moment transport equations are extended to take into account strongly variable density effects. Model combinations considered are assessed simulating piloted partially premixed flame. The obtained results agree well with experimental data.


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