Alternative Resources of Shock-Free Mild Initiation in Explosive Regimes

3 Alternative Resources of Shock-Free (Mild) Initiation in Explosive Regimes 

A fundamental unsolved problem of combustion theory is the conditions and a mechanism for spontaneous transition of low-velocity deflagration modes to detonation - DDT. This issue is very important for hydrogen -i- air mixtures, especially for questions about the DDT area and structure loads occurring at the DDT. 

Lack of completed theoretical models and the vagary of the present conceptions, compel one to perform more large-scale tests, but, unfortunately, all such tests have not resulted in comprehensive conclusions. At the same time, the dynamics of some accidents and their consequences are impossible to explain by traditional concepts of combustion modes. 

Descriptions of accidents and exploratory research has revealed an alarming possibility and even the reality of a shock-free DDT that is triggered without external initiators. There is an assumption that the DDT does not result from supersonic energy release as in HE explosions (explosions of powerful charge or a donor volume of gas/heterogeneous mixtures). 

It is obvious, that information about the potential of spontaneous or forced DDT acceleration is of practical use (blast protection issues, operation of power plants). 

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