What is the role of wavefront in high explosives?

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The discussion centers on the distinction between detonation and combustion in high explosives, emphasizing that detonation occurs at supersonic speeds while combustion is subsonic. In internal combustion engines, avoiding detonation is crucial to prevent damage to components like piston heads, which poses challenges for technologies like Pulse Detonation Engines. The conversation references how deflagration, even in rapid flame scenarios, is significantly slower than detonation, which involves a supersonic shock wave. The definitions are not universally clear, as many still label engine reactions as "explosions." Understanding these differences is essential for advancements in explosive technologies and engine design.
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How slow can an explosion possibly be?
 
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I think the generally accepted difference between "detonation" and "combustion" is wether the reaction takes place at supersonic speed for the medium being burned.

In an internal combustion engine, for example, care is taken to avoid a feul/O2/pressure combination that will "detonate" the fuel in the cylinder, because such an explosion will damage the piston heads (this is one of the main engineering obsticals to Pulse Detonation Engines). Although I've never seen it explicitly stated, the difference between detonation and combustion is always discussed in terms of a supersonic or a subsonic shockwave.

For example, http://www.popsci.com/popsci/aviation/article/0,12543,473272-2,00.html no pulse detonation states that...

In deflagration—even in "fast flame" situations ordinarily called explosions—that reaction moves at tens of meters per second at most. But in detonation, a supersonic shock wave slams down the tube...
.

Not a clear-cut definition, as most people would refer to what goes on inside an engine cylinder as an "explosion".
 
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