Chapman-Jouguet CJ Condition

An expl material (solid, liq or gaseous) on proper initiation moves from right to left at deton velocity and passes into the deton zone which is stationary in space. Conditions thruout the deton zone are steady. The tremendous increase in thermal motion of the atoms or molecules as-they pass into the shock zone causes chemical reactions of great rapidity. When the expl products reach the end of the reaction zone they are in chem equilibrium. They can be maintained at these conditions if they are contained by a piston which moves uniformly to the left at the same speed at which the products emerge from the reaction zone. This speed is identical with the local velocity of sound in the gaseous products (See Fig 1 from Ref. l) 

See also Detonation, Chapman-Jouguet Theory and also under Detonation, Theories of 

Its investigation by the Inverse Method is discussed by W.W. Wood W. Fickett in Physics of Fluids 6, 648-52(1961) 

Refs 1) W.G. Penney, ProcRoySoc 204A, 3-4 (1950) 2) Taylor (195 2), 73ff 

A process in which the velocity of the combustion products is exactly sonic at the equilibrium temperature and pressure of the products (CJ condition), and the velocity of the front relative to the undisturbed medium ahead is supersonic. (The same considerations apply 

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Chapman-]ouguet (CJ) Condition. See Detonation, Chapman-Jouguet (CJ) Condition... 

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