Effect of Temperature and Concentration Non-uniformity on Shock-Free Detonation Initiation

4 Effect of Temperature and Concentration Non-uniformity on Shock-Free Detonation Initiation 

As a rule, DDT processes are considered on the basis of a tacit assumption that there are no spatial temperature or concentration gradients of reagents in the system. However it was Ya. B. Zeldovich who pointed out that under normal DDT conditions, there was a potential for temperature and concentration non-uniformity (TCN) due to chaotic molecular motion in a gas mixture [23]. In real life, accidents resulted in the release of chemical compounds leading to the generation of temporary configurations with temperature and concentration variations expressed in fields of initial products or semi-products of incomplete chemical conversion. The operation of specified power conditioning devices also result in forcibly formed TCN. 

Most expressed TCN areas can be found in the combustion zone of a liquid jet engine. Due to the accepted scheme of carburetion, there is a space near the 

8 Shock-Free and Spontaneous Initiation of Explosive Regimes 

In another widely used device, a compressor, there is a zone in the gas with constantly growing temperature. Due to cold meshes and cyclic emptying/filling of the cylinder, hot spots (HS) with distribution throughout the volume, temperature and fuel/semi-products concentrations are formed in internal-combustion engines (ICE) [25]. Ionizing radiation of the fuel components may turn out to be a substantial source of mixture composition non-uniformity. Concentration of active particles may vary along a ray, which may affect the dynamics of an explosion. 

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