Investigation of dynamics of hydrogen-rich flames, development of new methods for validation of mechanisms of chemical kinetics and for model reduction
Energy Process Engineering
Mathematics
Theoretical Chemistry: Molecules, Materials, Surfaces
Final Report Abstract
The onset of diffusive-thermal instabilities and the dynamics of oscillations of combustion waves propagating in hydrogen-oxygen-inert mixtures was studied within the models with detailed mechanisms of reaction in various configurations, including freely propagating flames, combustion fronts stabilized on porous planar and cylindrical burners. Detailed parametric investigation of the critical conditions for the emergence of instabilities, amplitude-frequency characteristics and dynamics of pulsating flames was undertaken. In particular, dependence on the initial temperature, pressure, equivalence ratio, the extent of dilution with one and two atomic inert gases, flame-wall interaction, flame curvature was quantified. It is demonstrated that the critical conditions and the frequency of oscillations are internal characteristics of combustion process, similarly to the laminar burning velocity. On the basis of the observations made the new method for verification of the detailed reaction mechanisms of hydrocarbon fuels combustion has been developed. It represents the main outcome of the project. The synergy of experimental measurement and numerical computations of the critical parameters for the onset of the diffusive-thermal instabilities and amplitude-frequency characteristics of the emerging pulsations. The numerical analysis shows the high sensitivity of these parameters on the choice of the detailed reaction mechanism. Additionally, the possibility of direct experimental measurements of these characteristics was demonstrated. The comparison of the computed and experimental results was undertaken and the feasibility of the approach was approved. An extension of the time scale decomposition based reduced model to treat rich hydrogen-air flames under the critical conditions near the onset of the thermal-diffusion instability was suggested and employed. It is shown how the 4D (4 dimensional in the system thermo-chemical state space) reduced chemistry slow manifold designed for a homogeneous system performs to address hydrogen/air oscillatory flames. The manifold is constructed for an auto-ignition problem for one mechanism and is applied to study critical values for the onset of pulsating flames and characteristics of the oscillatory flame fronts with a number of wellestablished and validated hydrogen combustion mechanisms. It was demonstrated that the implicit formulation of reduced chemistry is capable of accurately predicting near limit behaviour in rich hydrogen/air systems in a wide range of system parameters and shows good extrapolation power of the approach. The demonstrated successful applicability of this method to describe on a uniform basis different flame phenomena such as ignition, flame propagation, and the onset of flame instabilities for an unprecedented large scale of mixture compositions and pressures opens up a new perspective to develop new and effective approaches to simulate various types of combustion configurations.
Publications
- 2017, Hydrogen/air burner-stabilized flames at elevated pressures, Comb. Flame, 184, 44-52
Gubernov, V.V., Bykov, V., Maas, U.
(See online at https://doi.org/10.1016/j.combustflame.2017.07.001) - Mechanisms performance and pressure dependence of hydrogen/air burner-stabilized flames (2018) Mathematical Modelling of Natural Phenomena, 13 (6) 51
Bykov, V., Gubernov, V.V., Maas, U.
(See online at https://doi.org/10.1051/mmnp/2018046) - The effect of dilution on the diffusive-thermal instability of the rich premixed hydrogen deflagration (2019) International Journal of Hydrogen Energy, 44 (21), pp. 11153-11160
Gubernov, V.V., Bykov, V., Maas, U.
(See online at https://doi.org/10.1016/j.ijhydene.2019.02.185) - ast-slow vector fields of reaction-diffusion systems (2020) IMA Journal of Applied Mathematics (Institute of Mathematics and Its Applications), 85 (1), pp. 67-86
Bykov, V., Cherkinsky, Y., Gol'dshtein, V., Krapivnik, N., Maas, U.
(See online at https://doi.org/10.1093/imamat/hxz035) - Combustion of rich hydrogen–air mixture stabilised near a cylindrical porous burner (2020) Combustion Theory and Modelling, 24 (4), pp. 650-665
Kichatov, B., Kolobov, A., Gubernov, V., Bykov, V., Maas, U.
(See online at https://doi.org/10.1080/13647830.2020.1734238) - Experimental observation of diffusive-thermal oscillations of burner stabilized methane-air flames (2020) Combustion and Flame, 213, pp. 202-210
Nechipurenko, S., Miroshnichenko, T., Pestovskii, N., Tskhai, S., Kichatov, B., Gubernov, V., Bykov, V., Maas, U.
(See online at https://doi.org/10.1016/j.combustflame.2019.12.016) - Hydrogen-oxygen flame acceleration in narrow open ended channels (2022) Combustion and Flame, 238, 111913
Bykov, V., Koksharov, A., Kuznetsov, M., Zhukov, V.P.
(See online at https://doi.org/10.1016/j.combustflame.2021.111913) - Diffusive-thermal pulsations of burner stabilized methane-air flames (2021) Combustion and Flame, 234, 111638
Mislavskii, V., Pestovskii, N., Tskhai, S., Kichatov, B., Gubernov, V., Bykov, V., Maas, U.
(See online at https://doi.org/10.1016/j.combustflame.2021.111638) - Model Reduction of Rich Premixed Hydrogen/air Oscillatory Flames by Global Quasi-Linearization (GQL) (2021) Combustion Science and Technology, 1-18
Bykov, V., Shashidharan, S., Berszany, E., Gubernov, V., Maas, U.
(See online at https://doi.org/10.1080/00102202.2020.1869729)
