Detonations in tubes

The mixtures were placed in transparent round latex flasks. Initiation was in the center. With their method, it was possible to record spherical detonation waves whose velocities were the same as when these mixtures were detonated in tubes. The waves usually originated very near the ignition source (electric spark or electric primer), but in some cases there was a brief predetonation period... 

Lee, J.H., Knystautas, R. and Perald, 0., "Criteria for Transition to Detonation in Tubes," Proceedings of the Twenty-First Symposium (International on Combustion. The Combustion Institute Pittsburgh, PA, 1986, pp. 1629-1637. 

J.H. Lee, The propagation of turbulent flames and detonations in tubes, in Advances in Chemical Reaction Dynamics, ed. by P.M. Rentzepis, C. Capellos (D. Reidel Publising company, Dordrecht, Holland, 1986) pp. 345-378... 

A deflagration-detonation transition was first observed in 1985 in a large-scale experiment with an acetylene-air mixture (Moen et al. 1985). More recent investigations (McKay et al. 1988 and Moen et al. 1989) showing that initiation of detonation in a fuel-air mixture by a burning, turbulent, gas jet is possible, provided the jet is large enough. Early indications are that the diameter of the jet must exceed five times the critical tube diameter, that is approximately 65 times the cell size. 

In addition, H2 is extremely sensitive to spark initiation, and can cause premature detons when ammo is being handled, is in-tube during launch, or is being steam-cleaned for reloading, purposes. A parallel reaction involves the release of NH3, which can combine with metals such as Cu in the presence of nitrates to form such extremely shock sensitive compds as tetramino cupric nitrate (Ref 17). To obviate these effects, desiccants such as silica gel may be added to the extent of 0.5% (Ref 12)... 

The PBX usually employed contains a high solids content expl such as PETN (PBXC-303(1), see in Tables 3, 4 5) which provides for steady -state deton in small cross-sectional channel or tubes (Fig 3). Indeed, this technique was de-... 

Solid particle-gaseous oxidizer systems have been studied because of applications to propints and expls (Refs 5 14), and hazards due to dust explns (Refs 1,3, 4, 6, 7, 10 15). Strauss (Ref 9) reported on a heterogeneous detonation in a solid particle and gaseous oxidizer mixt the study concerned A1 powder and pure oxygen in a tube. Detonations initiated, by a weak source were obtained in mixts contg 45-60% fuel by mass. Measured characteristics of the detonations agreed with theoretical calcns within about 10%, and detonation pressures of up to 31 atms were observed. With regard to solid particle-air mixts, detonations have not been reported only conditions for expln have been studied (Ref 2)... 

In the early studies [22,24,39] on propagation of detonation in very rough tubes, the steady propagation velocities as low as 50% of the normal CJ value have been observed. Such low-velocity detonations have been referred to as quasi-detonations [4]. 

Photographic study of the structure and propagation mechanisms of quasi-detonations in rough tubes. Prog. Astr. Aeron., 138, 223, 1990. 

Typical soot patterns of the detonation in a 2H2 + Oj + 7Ar mixture at 90 torr initial pressure in a rectangular (3 Vi in. x 1 Vi in.) tube. (Reprinted from Strehlow, R.A., Astronaut. Acta, 14, 539,1969. With permission.)... 

Numerical simulation of a spirming detonation in Hj/air mixture in a circular tube at various times. Gray and green space isosurfaces in pressure are the detonation front and the pressure of 6 MPa. White arrow propagating direction of the detonation front, pink arrow rotating direction of the transverse detonation. TD—transverse detonation, and LT—long pressure trail. (Reprinted from Tsuboi, N., Eto, K., and Hayashi, A.K., Combust. Flame, 149,144,2007. With permission.)... 

Yu.N. Denisov and Ya.K. Troshin, Pulsating and spinning detonation of gaseous mixtures in tubes. Doklady Akad. Nauk. SSSR, 125,110-113,1959. 

N. Tsuboi, K. Eto, and A.K. Hayashi, Detailed structure of spinning detonation in a circular tube. Combust. Flame, 149, 144-161, 2007. 

Processing and Uses. Polystyrene is an outstandingly good injection molding material. In this process the material is melted and forced through dies into a mold where it cools and solidifies. The process is very adaptable and is particularly suitable for the mass-production of small articles. Components for the electrical industry, objects for everyday use (buttons, combs, tube tops, fountain pens, etc.) and also articles for the military field (components for detonators in grenades, parts of gas-masks etc.) were manufactured in this way at that time. 

When the tube is closed at one end and ignited there, the propagating wave undergoes a transition from subsonic to supersonic speeds. The supersonic wave is called a detonation. In a detonation heat conduction and radical diffusion do not control the velocity rather, the shock wave structure of the developed supersonic wave raises the temperature and pressure substantially to cause explosive reaction and the energy release that sustains the wave propagation. 

In transition of detonation from a rigid-wall tube into a larger volume, the detonation will cease if the tube is of smaller diameter than the critical one for a weakly confined or unconfined expl. Whereas, when the diam is greater than the critical one, an outward-gping deton wave will arise in a certain time period after transition, and the explosive will detonate in the larger volume... 

The cutoff observed by Rozing Khariton (Ref 1) in detonation of explosives in tubes of small diameter and also discussed in the book of ZeTdovich Kompaneets (Ref 8, pp 213-16) is an abrupt extinction of the detonation by rarefaction waves from the sides of the charge reaching the axis before completion of the chemical reaction. It... 

Shekhter (1959), 417-28 (Transition of combustion to detonation in gases) 5) G.D. Salamandra et al, Formation of Detonation Wave During Combustion of Gas in Combustion Tube , 7thSympCombstn(1959), pp 851-55 6) Andreev Belyaev (i960),... 

Woodhead (Ref 16) reported in the paper entitled Advance Detonation in Tubular Charge of Explosive , that a deton proceeding axially within the wall of a hollow tube of HE bad a rate higher than normal by several hundred cm/sec and was, itself, outdistanced by a luminous wave within the hollow. This luminous wave moved at almost twice the deton vel. When the far end of the tube was closed with a plug of HE the luminous wave initiated on striking... 

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