Shockwaves

Glanzer K, Quack M and Troe J 1976 A spectroscopic determination of the methyl radical recombination rate constant in shockwaves Chem. Phys. Lett. 39 304-9... 

Holian B L and Lomdahl P S 1998 Plasticity induced by shockwaves in nonequilibrium molecular-dynamics simulations Soienoe 280 2085-8... 

If a particularly parallel beam is required in the chamber into which it is flowing the beam may be skimmed in the region of hydrodynamic flow. A skimmer is a collimator which is specially constructed in order to avoid shockwaves travelling back into the gas and increasing 7). The gas that has been skimmed away may be pumped off in a separate vacuum chamber. Further collimation may be carried out in the region of molecular flow and a so-called supersonic beam results. When a skimmer is not used, a supersonic jet results this may or may not be collimated. 

Gas Transport. Initially, ia a vessel containing air at atmospheric pressure, mass motion takes place when temperature differences exist and especially when a valve is opened to a gas pump. Initial dow ia practical systems has been discussed (29), as have Monte Cado methods to treat shockwave, turbulent, and viscous dow phenomena under transient and steady-state conditions (5). 

A detonation shock wave is an abrupt gas dynamic discontinuity across which properties such as gas pressure, density, temperature, and local flow velocities change discontinnonsly. Shockwaves are always characterized by the observation that the wave travels with a velocity that is faster than the local speed of sound in the undisturbed mixtnre ahead of the wave front. The ratio of the wave velocity to the speed of sound is called the Mach number. 

The apertures in sintered metal elements can be made so small that this arrester is able to quench detonations provided that it has sufficient mechanical strength. Particular care is required to ensure a secure anchorage of the sintered element to prevent leakage around the element caused by the impact of the shockwave (HSE 1980). 

Some designs of hydraulic (liquid seal) flame arresters have been sric-cesshilly tested for hydrogen service. NAO has designed and snccessfully tested and provided a hydraulic flame arrester for hydrogen-air applications (Straitz 1999). This design is for detonations and has dual liquid seal chambers with shockwave breakers. Rao (1980) also provides information... 

PETN is an effective underwater expl. Its shockwave energy and bubble energy relative to Pentolite (see in this Vol) are 1.15 and 1.13, respectively (Ref 21 a)... 

Non-isentropie compression across shockwave 177 Non-isothennal flow 159... 

SHOCKWAVES FOR INDUSTRIAL APPLICATIONS edited by Lawrence E. Murr... 

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. 

The energy of fast fluid flow can be utihzed to intensify processes in chemical reactors and there are two basic ways of doing it by purposefully creating the cavitation conditions in the reacting liquid or by using a supersonic shockwave for fine phase dispersion. 

Mattick, A.T., Russell, D.A., Hertzberg, A., and Knowlen, C. (1995) Shock controlled chemical processing, in Shockwaves at Marseille, Proceedings... 

Temperature, shock, shockwaves, friction and light may be the physical agency of instability. Unsaturated organic substances can sometimes undergo violent chemical transformations under the influence of some of these but do not come within the above definition. In these specific cases, dangerous chemical reactions, which often involve catalytic impurities, are the cause and are treated in chapter 4 as dangerous reactions . 

The difference between this test and the previous one is that layers of screens are added between the substance and the explosive in order to measure tiie shockwave effect of the detonator on the substance. 

Carbon disulphide burns in nitrogen monoxide and this combustion can be explosive. With dinitrogen tetroxide the mixture is supposed to be stable up to 200°C but a shockwave or a spark can cause the mixture to detonate. 

Walker, Stephen. Shockwave Countdown to Hiroshima. New York Flarper Collins, 2005. 

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. 

Akerman, L. A. et al., Combustion, Explos., Shockwaves, 1987, 23, 178 Calcium chloride and oxide catalyse the second, violent, stage of ammonium perchlorate decomposition and increase the shock sensitivity of mixtures with sugar. 

Gorbunov, V. V. et al., Combustion, Expls, Shockwaves, 1986, 22, 726 Not merely cupric oxide, but the fluoride, chloride and sulfide all form mixtures with heats of combustion above 2 kJ/g. The equivalent lead compounds are less active. 

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