The convergence of combustion models and compliance with the Kolmogorov scaling of turbulence

The Dry-Low-NOx (DLN) Micromix combustion technology has been developed as low emission combustion principle for industrial gas turbines fueled with hydrogen or syngas. The combustion process is based on the phenomenon of jet-in-crossflow-mixing. Fuel is injected perpendicular into the air-cross-flow and burned in a multitude of miniaturized, diffusion-like flames. The miniaturization of the flames leads to a significant reduction of NOx emissions due to the very short residence time of reactants in the flame. In the Micromix research approach, CFD analyses are validated towards experimental results. The combination of numerical and experimental methods allows an efficient design and optimization of DLN Micromix combustors concerning combustion stability and low NOx emissions. The paper presents a comparison of several numerical combustion models for hydrogen and hydrogen-rich syngas. They differ in the complexity of the underlying reaction mechanism and the associated computational effort. For pure hydrogen combustion a one-step global reaction is applied using a hybrid Eddy-Break-up model that incorporates finite rate kinetics. The model is evaluated and compared to a detailed hydrogen combustion mechanism derived by Li et al. including 9 species and 19 reversible elementary reactions. Based on this mechanism, reduction of the computational effort is achieved by applying the Flamelet Generated Manifolds (FGM) method while the accuracy of the detailed reaction scheme is maintained. For hydrogen-rich syngas combustion (H2-CO) numerical analyses based on a skeletal H2/CO reaction mechanism derived by Hawkes et al. and a detailed reaction mechanism provided by Ranzi et al. are performed. The comparison between combustion models and the validation of numerical results is based on exhaust gas compositions available from experimental investigation on DLN Micromix combustors. The conducted evaluation confirms that the applied detailed combustion mechanisms are able to predict the general physics of the DLN-Micromix combustion process accurately. The Flamelet Generated Manifolds method proved to be generally suitable to reduce the computational effort while maintaining the accuracy of detailed chemistry. Especially for reaction mechanisms with a high number of species accuracy and computational effort can be balanced using the FGM model.

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Large eddy simulation of methane–air deflagration in an obstructed chamber using different combustion models

Journal of Loss Prevention in the Process Industries ◽

10.1016/j.jlp.2012.04.008 ◽

2012 ◽

Vol 25 (4) ◽

pp. 730-738 ◽

Cited By ~ 25

Author(s):

Xiaoping Wen ◽

Minggao Yu ◽

Zhichao Liu ◽

Wence Sun

Keyword(s):

Large Eddy Simulation ◽

Combustion Models ◽

Eddy Simulation ◽

Large Eddy

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A lagrangian based scalar pdf method for turbulent combustion models

KSME International Journal ◽

10.1007/bf02984260 ◽

2004 ◽

Vol 18 (8) ◽

pp. 1470-1478 ◽

Cited By ~ 1

Author(s):

Hee-Jang Moon ◽

Roland Borghi

Keyword(s):

Turbulent Combustion ◽

Combustion Models

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Attractors And Turbulence for Some Combustion Models

Dynamical Issues in Combustion Theory - The IMA Volumes in Mathematics and its Applications ◽

10.1007/978-1-4612-0947-8_8 ◽

1991 ◽

pp. 213-228 ◽

Cited By ~ 1

Author(s):

Martine Marion

Keyword(s):

Combustion Models

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Experimental and Theoretical Study on Three Combustion Models for the Determination of the Performance Parameters of Nitrocellulose - Based Propellants

Revista de Chimie ◽

10.37358/rc.20.9.8320 ◽

2020 ◽

Vol 71 (9) ◽

pp. 87-97

Author(s):

Titi Paraschiv ◽

Tudor Viorel Tiganescu ◽

George Ovidiu Iorga ◽

Raluca Elena Ginghina ◽

Octavian Constantin Grigoroiu

Keyword(s):

Chemical Composition ◽

Energetic Materials ◽

Specific Volume ◽

Flame Temperature ◽

Performance Parameters ◽

Heat Of Explosion ◽

Combustion Gases ◽

Combustion Models ◽

Double Base

Nitrocellulose based propellants are the main materials used for ballistic and rocket applications. The chemical composition of the propellants, the loading density and propellant grain geometry are the decisive parameters that influence the performance parameters in ballistic application. In this paper the authors evaluate three models of combustion for energetic materials for the determination of heat of explosion and specific volume together with the adiabatic flame temperature. The authors select six types of propellant (two simple base propellants, two double base propellants based on nitroglycerine and two triple base propellants based on nitroguanidine) and the authors determined the heat of explosion and specific volume using a bomb calorimeter and a Julius-Peters device. The results obtained from the combustion models were compared to the experimental results and assumptions were done on the influence of pressure and temperature on the chemical composition of combustion gases produced by the confined deflagration of nitrocellulose-based propellants.

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