Numerical modeling of an explosion plasma generator, taking into account radiative energy transport and evaporation of the walls

Romanov, G. S.; Urban, V. V.

doi:10.1007/bf00824805

Cited by 6 publications

(4 citation statements)

References 2 publications

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“…Thus, the arguments based on the approximate equality of the phase and mass velocities allow The flow of gas streams in the compression chamber is non-stationary, two-dimensional, with shock waves of varying intensity and ionized gas. The exact calculation of such a complex flow requires numerical modeling, which was made in References [18][19][20][21]. In these papers are proposed a simple method to estimate this flow based on the following considerations.…”

Section: Resultsmentioning

confidence: 99%

Estimation of Dense Plasma Temperature Formed under Shock Wave Cumulation

et al. 2020

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The research was carried out by means of implosion plasma generators with conical and hemispherical compression chambers to conduct a quantitative assessment of the boundary temperature of super dense plasma jets. It was proved experimentally that nuclear transformations in metals are caused by the impact of super dense plasma jets (11, ..., 12) × 103 kg/m3. The boundary temperature of these jets was evaluated. It was estimated that the nominal boundary temperature of the studied implosion plasma generators is 106 К. The pressure in the target at the penetration of the super dense jet (~12,000 kg/m3) at the speed of 28,000 m / sec is more than 30 ТPa. The boundary temperature was estimated and proved to depend on the pre-determined values only slightly. It was experimentally established that stable isotopes of manganese Mn55 (up to 27%) are formed in iron targets as a result of high temperature plasma jet penetration. The appearance of manganese must be related to iron transformation into stable isotopes Fe56 and Fe54. The obtained results may be applied for investigating structural changes in metals under the conditions of impulsive super high temperatures and pressures. This method can be also used as a testing ground for studying the physical conditions of forming chemical elements as well as super dense plasma jets.

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Section: Resultsmentioning

confidence: 99%

Estimation of Dense Plasma Temperature Formed under Shock Wave Cumulation

et al. 2020

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“…The second temperature jump behind the front of the primary Mach wave, the formation of which is typical for devices with cylindrical symmetry [53], has physical features. In devices that are conical targets [13,14], wedge-shaped cavities [4,54], or known designs of Voytenko generators [15,45], irregular refl ections of shock waves occur with the formation of a three-wave shock confi guration in devices with cylindrical symmetry of elements (G. A. Adadurov, S. S. Batsanov, O. N. Breu sov, A. A. Deribas, A. N. Dryomin, S. V. Pershin, A. M. Staver (1965)(1966)(1967)(1968)(1969)(1970)(1971)(1972)(1973)(1974)(1975)(1976)(1977)(1978)(1979).…”

Section: Fig 1 Diagram Of An Explosive Generator That Forms a Fl At F...mentioning

confidence: 99%

“…We use the above assumptions about the causes and mechanisms of the formation of isotopes and chemical elements under the condition of a converging spherical or cylindrical front of a strong shock wave. One of the known methods for producing the iron-55 isotope is to irradiate the 56 Fe and 54 Fe isotopes with neutrons (Dwight D. J., Lorch E. A., Lovelock J. E. (1976). The 55 Fe isotope has a halflife of 2.737 years.…”

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confidence: 99%

On the mechanism of ionization of atoms at compression of a substance by front of the converging shock wave

Soboliev¹,

Hapieiev²,

Skobenko³

et al. 2022

Nauk. visn. nat. hirn. univ.

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Purpose. To study changes in the microstructure of metals after exposure to high-energy plasma jets formed by the cumulation of gas-dynamic flows in a conical target. To estimate the expected state of matter in a strong shock wave compression, taking into account the change in volumetric energy density at the moment of transformation of a solid body plasma into nuclear matter. Methodology. The technique of laser initiation of a profiled front of detonation waves in explosive charges and the corresponding profile of shock waves in materials, methods and techniques for measuring the dynamic parameters of shock-compressed substances are used. Findings. An experimental study on the physicochemical state of a substance that has been processed with extremely high pressures and temperatures during compression by converging shock waves in conical targets has been carried out. Scientific results of physical and mathematical modelling of converging shock waves are analysed. Originality. For the first time, the formation of symmetric plasma jets during gas compression in conical targets has been experimentally observed. For the first time, metallo-physical studies on the microstructure of cast iron and steel have been carried out. These studies were made after the action of high-energy dense plasma jets with a temperature of (2.52.8) × 106K and a pressure 1.12 × 1012 arising from the collision of the jet with a barrier. Iron-55 and copper-64 isotopes were found in the cast iron microstructure near the surface formed by the action of the plasma jet. The main components of the plasma jet were gaseous oxygen, nitrogen, argon, and atomic iron, copper and gold. The fact of formation of isotopes is the result of nuclear reactions. One of the main conditions for the implementation of such reactions is a dense high-temperature plasma. It is assumed that under the action of a strong shock wave in a conical target, in addition to the synthesis reaction, other nuclear reactions with heavy elements can be realized. The ideas about the expected state of matter in a compression shock wave are presented, taking into account the change in the volumetric energy density at the moment of transformation of a solid body plasma into nuclear matter. Practical value. The proposed technique for conducting experimental studies on a shock-compressed substance under the action of extreme temperatures and pressures in conical targets using laser initiation of chemical explosives is of practical importance. The idea of the expected state of matter in the shock wave is also important.

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“…Estimates of thermodynamic parameters and characteristics of shock-compressed matter make it possible to understand the evolution of fl ows, especially in the vicinity of the top of a cone (center of the sphere) or edge of a wedge (axis of the cylinder), the tendency of the development of the process of convergence of shock waves and arising physical eff ects [15][16][17]. It has been experimentally established for the fi rst time [18,19] that the entry of a metal striker (piston) into the cavity of the cone at a supersonic speed is accompanied by the emergence of two axisymmetric gas jets in the region of the apex directed along the axis of the cone in opposite directions. In all experiments, the jets burned through the metal body of the cone and the striker, indicating that one jet was directed towards the moving striker fi lling the cavity, and the other toward the top of the cone.…”

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confidence: 99%

Formation of converging cylindrical detonation front

Soboliev¹,

Skobenko²,

Usyk³

et al. 2021

Nauk. visn. nat. hirn. univ.

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Purpose. To develop a laser method for initiating a converging cylindrical front of a detonation wave and a method for calculating the kinematic parameters of the cylindrical shell walls, accelerated by the pressure of the detonation products of an external explosive charge. Methodology. An experimental technology for the manufacture of a photosensitive explosive composite and an experimental technique for igniting the surface of its layer with an extended laser beam without the use of a fiber-optic cable are used. The results of simulation modeling the Monte Carlo method were used to study the effect of illumination on the process of ignition of explosives by laser pulsed radiation. For the selected type of photosensitive explosive composite, its explosive and optical characteristics, the distance from the surface of the explosive charge to the lens scattering the laser beam, and taking into account the total area of the expanded beam, the regularities of the distribution of the radiation energy density over the vertical and horizontal sections of the laser beam were studied. Findings. The analysis of the scientific and technical level of methods of shock-wave processing of materials in the region of ultrahigh pressures from the point of view of the fundamental value of the cumulation of energy in the waves of a converging cylindrical detonation and shock front is carried out. Physicomathematical modeling was carried out and the regularities of pressure increase in the wave front were established in the process of approaching the shell walls to the axis. The scientific results of modeling converging cylindrical shells under the influence of the pressure of the explosion products have been analyzed. A method for laser initiation of a converging cylindrical front of a detonation wave has been developed, and a method for calculating the kinematic parameters of the converging walls of a cylindrical shell has been proposed. Originality. A technique has been developed for determining the energy characteristics of an expanded laser beam, calculating the laser radiation energy required to initiate detonation simultaneously on the entire lateral cylindrical surface of a photosensitive explosive composite. The idea of technical implementation of the cumulation of converging cylindrical detonation and shock waves was developed further. A technique has been developed for the numerical determination of the change in the internal average compression rate of the shell during the movement of its walls towards the axis for various ratios of its external radius to the wall thickness and taking into account the increase in pressure in the converging detonation front. Practical value. For the first time, a method for laser initiation of a converging cylindrical front of a detonation wave was developed and a device was tested that forms a converging cylindrical front of a detonation wave and a corresponding shock front in the material under study by the impact of a metal shell converging to the axis. The core of the device is a laser explosive initiation system that uses light-sensitive explosive composites to initiate an explosive charge.

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Numerical modeling of an explosion plasma generator, taking into account radiative energy transport and evaporation of the walls

Cited by 6 publications

References 2 publications

Estimation of Dense Plasma Temperature Formed under Shock Wave Cumulation

Estimation of Dense Plasma Temperature Formed under Shock Wave Cumulation

On the mechanism of ionization of atoms at compression of a substance by front of the converging shock wave

Formation of converging cylindrical detonation front

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