Detonation waves in polydisperse bubble media

Detonation waves in polydisperse and monodisperse bubble media are studied experimentally. The data on the critical initiation conditions and the structure and properties of detonation waves are obtained. Translated fromFizika Goreniya i Vzryva, Vol. 34, No. 6, pp. 71–76, November–December 1998.     

Detonation waves in multicomponent bubbly media

Novosibirsk. Translated from Fizika Goreniya i Vzryva, Vol. 29, No. 1, pp. 110–117, Junuary-February, 1993     

Detonation waves in a reactive supersonic flow

A supersonic hydrogen—air flow is studied in detail, in particular, the fields of gas-dynamic parameters and chemical homogeneity of the mixture in various cross sections of the duct. The processes of excitation and propagation of a detonation wave in the downstream and upstream directions are considered. The detonation-wave velocity with respect to the mixture flow is found to differ from the nominal Chapman—Jouguet velocity for a quiescent mixture: the detonation-wave velocity is higher if the wave moves upstream and lower if the wave moves downstream. Some hypotheses on the reasons for these deviations of the experimentally measured velocity from the nominal value are given. __________ Translated from Fizika Goreniya i Vzryva, Vol. 42, No. 5, pp. 85–100, September–October, 2006.     

Detonation properties of the synthesis gas

Investigated parameters of combustion and detonation of mixtures of the synthesis gas with oxygen and air are presented. The ratios between carbon oxide and hydrogen and between the fuels and oxidizer are varied within wide ranges. The critical energy of detonation initiation is determined. __________ Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 6, pp. 90–96, November–December, 2007.     

Detonation in a relaxing gas and relaxational instability

Conclusions It is well known that the one-dimensional structure of DW is encountered relatively rarely in practice. As a rule, detonation waves have a three-dimensional pulsating structure (triple configurations [10, 24]). There is no question that the one-dimensional model of detonation studied here cannot and does not pretend to describe the nature and structure of three-dimensional pulsations caused by the thermal or relaxational instability of the wave front. In the case of a pulsating detonation the proposed model, like the classical theory (limit of small ), refers to time-averaged gasdynamic quantities and to the selection rule for the velocity of detonation. In addition, the one-dimensional model can be used (see the section concerning the relaxational instability) as a starting point for the analysis of the instability of DW.Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 22, No. 5, pp. 75–86, September–October, 1986.     

Detonation in a relaxing gas with two heat-producing reactions

Novosibirsk. Translated from Fizika Goreniya i Vzryva, Vol. 28, No. 3, pp. 89–93, May–June, 1992.     

Detonation combustion of gas mixtures using a hypervelocity projectile

This paper considers, from a unified point of view, problems of initiation of detonation combustion of a gaseous mixture using a hypervelocity projectile (HVP), The consideration is based on the energy criterion forHVP-induced detonation initiation. Experimental results are given that support the correctness of the criterion in a wide range of diameters (5–250 mm),HVP velocities (800–3500m/sec), and compositions of explosive mixtures (from active fuel-oxygen to hard-to-detonate fuel-air mixtures). The processes ofHVP interaction with an explosive mixture are classified. The previously unknown effect of jet formation of a detonation wave from a ballistic wave (at velocities less than the detonation velocities) was discovered for anHVP with a plane bow. Lavrentśev Institute of Hydrodynamics, Siberian Division, of the Russian Academy of Sciences, Novosibirsk 630090. Translated from Fizika Goreniya i Vzryva, Vol. 33, No. 5, pp. 85–102, September–October, 1997.     

Detonation nanodiamonds simultaneously purified and modified by gas treatment

The gas phase method of simultaneous purification and modification of detonation nanodiamond has been developed that allows producing nanodiamonds of the superior quality and with high stability of suspensions. The technology uses a fluidized bed reactor fed with an air enriched with oxygen or ozone. In the reactor, the non-diamond by-products of detonation synthesis, mostly graphite, are reacted to ozone at the elevated temperature and converted to CO₂ or CO. Simultaneously the surface of detonation nanodiamonds is depleted of non-diamond carbonaceous by-products of the detonation synthesis and enriched with oxygen-containing chemical groups. The technology is an attractive alternative to a commonly used method of detonation soot treatment with concentrated acids or other strong liquid oxidizers. In this paper, we report on the reactor, method and physical chemical properties of nanodiamonds processed from soot by treatment in air enriched with ozone. The technology is environmentally friendly and may find wide application in industry.     

Ignition of filtration gas combustion waves by the flame of the filtered gas

Mathematical modeling of ignition of filtration gas combustion waves in a porous medium with external initiation of combustion by the filtered gas is performed. It is shown that the surface temperature of the porous medium at which the flame enters the latter is a function of system parameters. The existence of the lower and upper flammability limits in terms of the gas filtration rate is found. Dependences of the ignition time on parameters of the porous medium are obtained, and their interpretation is given.     

Detonation in TATB Hemispheres

Streak camera breakout and Fabry‐Perot interferometer data have been taken on the outer surface of 1.80 g/cm³ TATB hemispherical boosters initiated by slapper detonators at three temperatures. The slapper causes breakout to occur at 54° at ambient temperatures and 42° at −54 °C, where the axis of rotation is 0°. The Fabry velocities may be associated with pressures, and these decrease for large timing delays in breakout seen at the colder temperatures. At room temperature, the Fabry pressures appear constant at all angles. Both fresh and decade‐old explosive are tested and no difference is seen. The problem has been modeled with reactive flow. Adjustment of the JWL for temperature makes little difference, but cooling to −54 °C decreases the rate constant by 1/6th. The problem was run both at constant density and with density differences using two different codes. The ambient code results show that a density difference is probably present, but it cannot be quantified.