Shock waves reactions behind

The Chapman-Jongnet (CJ) theory is a one-dimensional model that treats the detonation shock wave as a discontinnity with infinite reaction rate. The conservation equations for mass, momentum, and energy across the one-dimensional wave gives a unique solution for the detonation velocity (CJ velocity) and the state of combustion products immediately behind the detonation wave. Based on the CJ theory it is possible to calculate detonation velocity, detonation pressure, etc. if the gas mixtnre composition is known. The CJ theory does not require any information about the chemical reaction rate (i.e., chemical kinetics). 

Data on the rate of the homogeneous reaction have been obtained by following the decay of ammonia behind shock waves. The stoichiometry of the ammonia decomposition is... 

This results in a successive diminishing of the detonation front. A process of this kind may stop detonation, provided no new detonation front develops within the compressed explosive behind the shock wave left by the terminated reaction. The new detonation wave would travel over the com-... 

It is considered that the detonation wave consists of a shock traveling at velocity D, followed immediately by a region of isen-tropic expansion and that the region of chemical reaction behind the shock is infinitely thin... 

Chaiken (Ref 5) reported that his prior streak camera studies of the shock initiation to deton of NM indicated the existence of a "hypervelocity wave moving behind the initiating shock front. It was suggested that the deton reaction wave originated be-... 

Cook (Ref 15) also reported that the shock transmitted thru a barrier into a transparent liq expl, appeared (from the partial opacity of the liq behind the shock front) to initiate some reaction at once. The high-velocity deton appeared, on the other hand, to start as a much more intense luminosity at one or more centers randomly distributed within the reacting liq. Often an intense flame is observed to flash across the region just traversed by the shock wave, at a velocity far above the normal deton vel, and upon reaching the shock front to start a high-order deton (See also Ref 17, p 13b)... 

Ibid, 28, 1437-41(1957) (Plane shock waves) and Ibid 29, 167-70(1958) (Oblique shock waves) 52) Dunkle s Syllabus (1957-1958). Properties of Shock Waves, which include Supported Shock Waves (pp 50-1) General Properties of Shock Waves (51-2) Detachment of Shock Waves (52-3) Conditions Behind Shock Front (53-6) Variability of Specific Heats (56-7) Relaxation Processes, Ionization, and Chemical Reaction (57-60) and Shock Waves in Solids (60). 

If the deton wave is a shock wave initiating chem reaction and continuously supported by energy thus set free, then it must be protected against the rarefaction which will always follow. This is impossible, if the velocity of small disturbances behind the wave is greater than that of the wave itself. In other words, if (a ) is the velocity of sound at Xj relative to the fluid there, (which itself moves with velocity Wj), and if ai+Wf exceeds the wave cannot be steady but must loose velocity. If a + is less than D, the wave can apparently remain steady. However, the condition a + W < D must, by reason of continuity, persist some little way into Xj Xs, say up to a section X1 (not shown in Fig 5). Then the chem energy released within X Xp can have no influence on what happens ahead of X and is therefore ineffective from the point of view of supporting the wave front. 

Wendlandt [10] emphasizes the analogy between the overcompressed detonation wave on the branch BFD and a simple compression shock wave without chemical reaction which is also overtaken and weakened from behind by rarefaction waves. In contrast, a detonation wave at the tangent point, for which the Chapman-Jouguet condition is satisfied, is similar to a sound wave and is transformed into a sound wave when the thermal effect of the reaction goes to zero. 

The oxidation of o-, m-, and p-xylenes with oxygen-argon mixtures were measured behind reflected shock waves. The main reaction paths have been determined by sensitivity and flux analyses and have been used to explain the slight differences in the reactivity.253... 

The thermal reactions of dihydrobenzo[c]furan 258 were studied behind reflected shock waves in a single pulse shock tube over the temperature range 1050-1300 K to lead to products from a unimolecular cleavage of 258 <2001PCA3148>. Intriguingly, carbon monoxide and toluene were among the products of the highest concentration, while benzo[f]furan, benzene, ethylbenzene, styrene, ethylene, methane, and acetylene were the other products. Trace amounts of allene and propyne were also detected. 

If the velocity of the reaction becomes fast enough and the reaction is sufficiently exothermic, the adiabatic expansion of our reacting zone will occur at a linear rate comparable with the velocity of sound. Under such circumstances a sharp pressure wave begins to be built up ahead of the reaction zone, and it can propagate as a shock wave of supersonic velocity in the unburned gases.As the shock front passes through the reaction mixture, it produces adiabatic compression. If the temperature in this adiabatically compressed zone behind the shock wave exceeds the... 

Chemical reactions behind a shock wave produced in a shock tube... 

---