Investigation of the dynamics of hydrogen-rich flames, development of new methods for validating mechanisms of chemical kinetics and model reduction

Summary

Nowadays, not only the development of practical devices using the combustion of hydrocarbons, but also theoretical research in the field of combustion and explosion physics, is based on the numerical treatment of mathematical models that apply the detailed kinetics of the oxidation reactions of hydrocarbons. Currently, there are a number of kinetic mechanisms specifically developed to describe the high-temperature combustion processes of hydrocarbons. These can contain hundreds to thousands of elementary steps, each with its own reaction constant. However, direct and indirect experimental measurements of these reaction constants are only possible to a very limited extent. As a result, the development of an accurate and reliable mathematical model of combustion wave propagation remains a challenging task and any additional method for verification and validation of the chemical mechanisms is of great value. In the proposed project, the authors recommend the development of a method for validation and verification of the hydrogen combustion mechanisms . Hydrogen combustion remains a current topic precisely because of its applications in energy storage technologies, especially in relation to the reduction of CO2 emissions. Safety aspects are particularly important, the assessment of which requires reliable mechanisms for describing explosion processes. In addition, hydrogen oxidation represents the common sub-mechanism of all known detailed mechanisms for the oxidation of hydrocarbons. At the same time, the numerical treatment of combustion processes in technically relevant geometries and flow conditions is not yet practically feasible due to the high dimensionality and large differences between the characteristic length and time scales. The dimensionality and rigidity of the system make numerical treatment significantly more difficult and lead to very high demands on computing power and storage space. For this reason, the development of reduced kinetic mechanisms represents another main topic of the proposed project. The proposed methodology will be based on the study of the dynamic characteristics of nonlinear combustion waves arising in complex combustion systems and on low-dimensional manifolds developed in the state space of the reacting system . The successful implementation of the project will open up new possibilities for verifying chemical mechanisms and significantly improve combustion theory and applications, including in the field of industrial use. The methods for automatic reduction of kinetic mechanisms will play a central role in numerical calculations for the control and optimization of combustion processes of hydrocarbons in complex geometries and flow conditions.

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