Shockwave propagation

Mass transport of the reactants and products is increased at the catalyst surface and in the solution due to the facilitated transport as a result of shockwave propagation. 

The main remaining limitation of these kinds of potentials is the lack of terms to represent chemical reactions. Some recent progress along these lines, particularly in the field of energetic materials, has been recently reviewed.[138] The most important developments have been achieved so far using reactive empirical bond order (REBO) potentials introduced by Brenner and coworkers.[139] The REBO potentials have been used mainly for simulations of shockwave propagation in simple diatomic or triatomic molecular crystals however, it is likely that these kinds of potentials will soon be extended to more complex systems. A reactive potential based on somewhat different bond order concepts has been used to calculate the initial shock-wave induced chemical events in RDX.[140] To date, to our knowledge, REBO potentials have not been applied to ionic crystals. 

Shockwave propagation in plasmas leads to polarization of the plasmas and specific electric effects (see, for example, Lieberman Velikovich, 1985 Kolesnikov, 2001 Ishig-mo, Kamimttra, Sato, 1995 Hershkowitz, 1985 Raadu, 1989 Maciel Allen, 1989 ... 

The model described has been applied to compressible air flow with Reynolds numbers in the range of 500 to 1,500. These values were obtained using Eq. 5 that is also valid for shockwave propagation in a narrow channel [2]. Further, based on the analysis of gas flow characteristics in silicon microchannels [6], the friction coefficient/has been found to be approximately 0.04 for a Reynolds number of 500, while for Reynolds numbers greater than 1,000, the friction coefficient becomes less than 0.005. 

Experiments with a miniature shock tube using low pressures to simulate the effects of small scale have shown qualitative agreement with the proposed model. The effects of scale are even more pronounced than what has been predicted by the model. Experimental and numerical investigations for incident shock Mach number of M = 1.2 have shown significant viscous effects for channel heights below 4 mm even at atmospheric pressure. That shockwaves propagate more slowly at low pressures in a narrow channel has been confirmed, but they may... 

Consider the one-dimensional situation, depicted in Figure 14.2, of a shockwave propagating upwards, with velocity V, through a fluidized suspension. The void fractions immediately below and above the shock are e and 2 respectively. (The jump condition derivations that now follow are less restricted than appears from Figure 14.2, in that the void fractions directly across the shock, e and 2, need not in general correspond to equilibrium conditions.)... 

The concept of linear burning rate is not confined to the reaction of a gas with a solid. The fuses on fireworks are designed to bum at a constant linear rate. The flame front on solid rocket fuel progresses at a constant linear rate. Both examples have two reactants (a fuel and an oxidizer) premixed in the soUd. Heat transfer limits the burning rate. These materials are merely fast burning. Unlike explosives, they not do propagate a sonic shockwave that initiates further reaction. 

L.P. Parshev, ZhPriklMekhan i TekhnFiz 1965(5), 130-31 CA 64, 3274(1966)(Calculation of the energy of a shock wave in water) 72a) W.A. Walker H.M. Sternberg, "The Chapman-Jouguet Isentrope and the Underwater Shockwave Performance of pentolite , 4thONRSympDeton (1965), pp 27-38(26 refs) 73) R. Cheret, "Theoretical Considerations on the Propagation of Shock and Detonation Waves , Ibid, pp 78-83 74) A.B. Amster et al, "Detona-... 

Detonation An exothermic reaction that propagates a shockwave through an explosive at supersonic speed (greater than 3300ft/sec). 

If the medium is explosive, an explosive chemical reaction must be produced immediately in the wave front because of the drastic temperature and pressure conditions. The propagation of the shockwave is maintained by the energy of the reaction. 

In this section we first present a series of results (Sec. 3.1) which show that molecular dynamics simulations can be used to directly link atomic scale chemistry to the continuum theory of detonations. We then show (Secs. 3.2 and 3.3) that complex initiation behavior can arise even within the simple AB Model I system. Taken together, the results reviewed in this section demonstrate that simulations using REBO potentials provide a powerful probe of the interplay between the continuum properties of shockwaves and the atomic scale chemistry induced in the initiation and propagation of condensed phasn detonations. 

Fig. 4. Snapshot of a detonation 12.5 ps after impact by a 6 km/s flyer plate. The shockwave is propagating from left to right. The two types of atoms are shown as open and solid circles.

---