Mechanisms of the development of intensive dynamic processes during hydrogen combustion in the combustion chambers of internal combustion engines

The combustion modes of hydrogen applied as a fuel in the combustion chamber of an internal combustion engine are analyzed. Flame development features and the formation of gasdynamic flows with the related pressure fluctuations in the combustor are analyzed based on the numerical modeling. It is demonstrated that the use of near-stoichiometric compositions of hydrogen–air mixtures is limited by the appearance of fast combustion modes characterized by the generation of intensive shock waves as a result of the unsteady combustion of the mixture and the developing thermoacoustic instability. The obtained result indicates that the generation of intensive pressure fluctuations has an alternative mechanism when using the hydrogen–air mixtures, in which self-ignition in hot spots in the region before the flame front and detonation are estimated to be unlikely.