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## Numerical and experimental study on detonation of hydrogen-air mixtures

#### Abstract

In this thesis a numerical investigation of hydrogen-air detonation parameters and calculations of characteristic detonation cell size were conducted and compared with experimental data. Simulations were performed by means of OpenFoam and a solver named ddtFoam, which is based on progress variable equation where the detonative source term accounts for autoignition effects. The calculations of the characteristic were based on ZND theory and used Cantera as well as SDToolbox libraries. Range of gaseous mixture compositions used in calculations varied between 20% and 50% hydrogen by volume. The 2D calculation geometry was a 9 m long pipe with the diameter of 0.17 m. The mesh consisted of 382 500 hexahedral cells. Simulations were performed for both, RANS and LES models. Introduction describes the aim of this thesis and outlines in a general way the detonation combustion process. Moreover, it illustrates the issue of investigating the detonation parameters and its meaning for general safety. The next chapter involves an overview of literature containing a theoretical introduction to detonation and ways how to mathematically model it. These mathematial models were used later in a numerical analysis. Based on the literature, the Chapman-Jouguet theory was described and the equations for Hugoniot curve and Rayleigh line in a p-v system were formulated. Additionally, the ZND theory was explained and the author showed the differential equations system which describes the ZND detonation. Furthermore, the chapter outlined basic physical an chemical properties of hydrogen and its mixture with air. The experiments were described in the next chapter, which details the test rig used for research and means of measuring the parameters. Furthermore, the instructions for performing the tests were introduced. Then the author went to describe the process of preparing simulations and overviewing the software used. The features and capabilities of OpenFoam were specified. The solver was presented as well, with detailed description of the combustion modelling mechanism and subgrid-scale functions. Moreover, the author specified all details of the mesh and turbulence models types applied. The next chapter outlines the means and equations used in the charateristic cell size calculations. Furthermore, the author specified various definitions of the reaction length and empirical formulas for obtaining results. Another chapter contains comparisons of experiments with simulations results as well as the characteristic cell sizes obtained in the experiments and their relation to the ZND theory calculations. Additionally, the author attempted to modify solver's default ignition delay tables in order to influence the detonation velocity. Finally, the author recapitulates the results obtained from numerical calculations in comparison with the experiments.
Diploma type
Engineer's / Bachelor of Science
Diploma type
Engineer's thesis
Author
Konrad Piotr Malik (FPAE) Konrad Piotr Malik,, Faculty of Power and Aeronautical Engineering (FPAE)
Title in Polish
Badania numeryczne i eksperymentalne detonacji mieszaniny wodoru i powietrza
Supervisor
Mateusz Żbikowski (FPAE/IHE) Mateusz Żbikowski,, The Institute of Heat Engineering (FPAE/IHE)Faculty of Power and Aeronautical Engineering (FPAE)
Certifying unit
Faculty of Power and Aeronautical Engineering (FPAE)
Affiliation unit
The Institute of Heat Engineering (FPAE/IHE)
Study subject / specialization
, Lotnictwo i Kosmonautyka
Language
(pl) Polish
Status
Finished
Defense Date
11-02-2016
Issue date (year)
2016
Pages
48
Internal identifier
MEL; PD-3516
Reviewers
Mateusz Żbikowski (FPAE/IHE) Mateusz Żbikowski,, The Institute of Heat Engineering (FPAE/IHE)Faculty of Power and Aeronautical Engineering (FPAE) Andrzej Teodorczyk (FPAE/IHE) Andrzej Teodorczyk,, The Institute of Heat Engineering (FPAE/IHE)Faculty of Power and Aeronautical Engineering (FPAE)
Keywords in Polish
detonacja, OpenFOAM, symulacja, eksperyment, wodór, komórki detonacji, Cantera, SDToolbox
Keywords in English
detonation, OpenFOAM, simulation, experiment, hydrogen, detonation cell size, Cantera, SDToolbox
Abstract in Polish
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urn:pw-repo:WUT584b9e0815aa498592f560f05038d569