Overcompressed and Undercompressed Detonation Waves

Detonation Waves, Overcompressed and Undercompressed. Zel dovich and Kompaneets stated (Ref 60, pp 97-100), that Aivazov Zel dovich. 

The calculation of parameters of overcompressed wave formed on detonation of 2H2+O2 mixture, has shown that upon transition from the wide pipe to the narrow one, an overcompressed wave should arrise in the narrow pipe for which the pressure is 1.36 times greater than the pressure in the normal detonation wave. In this case the velocity of overcompressed wave was equal to 1.04 times the vel of normal deton wave, but 

Overcompressed detonation waves were also observed by Troshin (Ref 55, p 789). He observed it not only in transfer of deton from the broad to narrow tube, but also immediately after transition of combustion to detonation. 

In his Fig I of the Hugoniot curve, shown on p 789, the JM branch corresponds to overcompressed detonation waves 

The possibility of the existence of under-compressed. waves is discussed by Zel dovich Kompaneets (Ref 60, pp 1,01-02). They connect the under compressed waves with an external artificial ignition, since in this case there is no igniting shock wave, and the molecular thermal conductivity of the combstn products from a raw mixt does not guarantee a sufficient vel of propagation of the regime. 

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Detonation Waves, Undercompressed. See under Detonation Waves, Overcompressed and Undercompressed Detonation Wave, Unstable. See under "Detonation Waves Transients in Propa -gation of Transient, Anomalous and Metastable (Unstable)... 

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