In the case of multipoint initiation of the side surface of a cylindrical charge in a section perpendicular to the axis, a detonation wave with a complex gas-dynamic structure is formed, which has the shape of a polygon with vertices at wave conjugation points. The sides of the polygon are always convex toward the charge axis. It is stated that a smooth cylindrical detonation wave with reverse curvature can be obtained by using special devices at initiation points: lenses made of an inert material. The dynamic characteristics of the material are experimentally determined, and the method for constructing the lens profile is substantiated. The operation of an initiation node and the formation of a cylindrical detonation wave in a charge are mathematically modeled. The specific features of the operation of a single initiating node and a node that is part of the experimental assembly are shown. The dynamics of axisymmetric compression by a converging detonation wave is presented and compared with calculations.

This article suggests profiling the surface of one of the welded plates in a special way during explosion welding. The principle and method of calculating the profile of the plate based on the materials and welding speeds of the plates are given. It is assumed that such profiling of the surface of the plate will allow to obtain more durable welded joints and even perform welding at a speed below the minimum collision speed for welding plates with smooth surfaces. As an example, a full calculation of plate profiling for specific collision parameters of welded plates is given.

To investigate the features of the processes inside the ramjet subsonic combustion chamber, a numerical model is used. The model is based on Reynolds-averaged Navier-Stokes equations along with turbulence, radiation and combustion models and considers solid fuel pyrolysis. Available in literature experimental data was used to validate the model. The dependences of the heat flow structure on the air flow are obtained. The effect of radiation heat transfer on the regression rate is shown.

The numerical simulation of the first stage of fiber-spinning process was performed. The single-mode Giesekus model was used for polymer fiber stress calculations. Fiber profiles, longitudinal velocity, tensile stress and apparent elongational viscosity were analyzed depending on the stretch speed and the degree of anisotropy of the polymer.

Numerical modeling was used to study the patterns of droplet deformation in two-phase Newtonian fluids flowing through a three-dimensional rectangular microchannel with a sharp narrowing. The elongation of single droplets of different viscosities was investigated in different channel zones. Calculations were carried out for different confinement parameter-the ratio of droplet diameter to the gap thickness. The increase in this parameter was shown to lead to the substantial increase in the droplet relative elongation. The effect of coalescence to microfiber formation in flowing emulsion was considered.

Abstract In order to investigate features of processes inside a combustor of a solid fuel ramjet a numerical model was employed. The model is based on Reynolds-averaged Navier-Stokes equations along with turbulence and combustion models and considers solid fuel pyrolysis. Experimental data from an earlier work was used to validate the model. Dependencies of air mass flux on some combustor performance parameters were obtained for different solid fuels.

The methods of mathematical modeling based on the latest experimental data are proposed to conduct a study of the cylindrical detonation process and gas dynamics of the explosion products. The numerical simulation of converging cylindrical detonation waves at multipoint initiation for the recent experiments in IPCP RAS was conducted. The results of the numerical simulation and the experiment are compared.

The pressure driven flow of a viscous incompressible fluid in a 2D channel with sudden contraction and expansion is investigated numerically. The attention is concentrated on studying conditions of occurrence of the elongational flow in a narrow section of the channel. To this end, interconnection between flow patterns and axial velocities is analyzed at different Reynolds numbers.

The results of numerical simulation of wave formation under an oblique impact of metal plates during explosion welding are presented. The numerical simulation was carried out on the basis of the elastoplastic approximation. It is shown that the elastoplastic behavior of metals may be a possible source of instabilities. Further evolution of the process of wave formation and the formation of a periodic wave structure of the interface are already determined by the hydrodynamic behavior of materials. The temperature at the contact boundary of plates obtained in the calculation exceeds the melting point. The calculated wavelengths coincide with the experimental data.

This paper is a preface to the proceedings of the XXXI International Conference on Equations of State for Matter, which was held in Elbrus settlement, in the Kabardino-Balkar Republic of the Russian Federation, during March 1-6, 2016. The conference was devoted to the seventieth anniversary of birth of Aleksey Vladimirovich Bushman (16.10.1946-6.12.1993), the author of classic works on equations of state for matter over a wide range of thermodynamic parameters on phase diagram.

The paper analyzes the disintegration of small cosmic bodies in a planetary atmosphere and most important facts observed during the fall of the Chelyabinsk superbolide: its speed loss during passage through the upper atmosphere, its strength and the character of destruction, the altitude of its explosion, and the energy release. Detailed data are presented on the aerodynamic phenomena accompanying the supersonic atmospheric entry and destruction of the superbolide. The strength of the original meteorite is evaluated as a function of its initial disintegration altitude. Principal data obtained on the collision between comet Shoemaker-Levy 9 and Jupiter are reported.

Because of the very high ion beam intensities which will become available with the advent of the new large scale facilities like SPIRAL2, the mechanical resistance of targets under beam impact has become a crucial problem due to the large specific power deposition by the projectile ions in the material. For experiments that require production of a specific higher charge state than the one produced by the LINAC, the beam stripper must remain intact during the experimental campaign over a long period of time. Numerical simulations have confirmed that a fixed stripper, which is continuously irradiated at the same spot, cannot be used and we propose an alternative scheme in which a wheel shaped aluminum stripper rotating at a rate of 2000rpm is used. The thermal load on the material is substantially reduced because a much larger area is now irradiated and our first test of simulations show that a steady state temperature, which is safely below the melting temperature of aluminum, is achieved due to heat conduction and radiation losses from the heated material.

In this paper we report on two-dimensional numerical simulations of heating of a rotating, wheel shaped target impacted by the full intensity of the ion beam that will be delivered by the SPIRAL2 facility at Caen, France. The purpose of this work is to study heating of solid targets that will be used to strip the fast ions of SPIRAL2 to the required high charge state for the FISIC (Fast Ion–Slow Ion Collision) experiments. Strippers of aluminum with different emissivities and of carbon are exposed to high beam current of different ion species as oxygen, neon and argon. These studies show that carbon, due to its much higher sublimation temperature and much higher emissivity, is more favorable compared to aluminum. For the highest beam intensities, an aluminum stripper does not survive. However, problem of the induced thermal stresses and long term material fatigue needs to be investigated before a final conclusion can be drawn.

Performing Fast Ion Slow Ion Collision (FISIC) experiments is a long standing project for atomic collision physicists. Whereas such experiments are currently performed by high energy physicists, ion ion collisions for atomic physics have so far been performed only in the case of slow ions, in the context of magnetically confined plasmas. Besides the fundamental interest in understanding the mechanisms involved in ion atom collisions, such studies are also motivated by various aspects of the energy deposition by fast ions in matter, including inertial confinement fusion plasmas, material modifications and biological effects [1]. With the advent of new facilities such as SPIRAL2 at Caen (France) which are able to deliver intense stable ion beams,the INSP team proposes a project named FISIC to explore ion ion collisions and their dynamics for heavy ions in the unknown regime of intermediate velocities. FISIC will use crossed beams of high intensities for which the charge state of both the incoming projectile ions (Fast Ions from SPIRAL2) and the target ionized medium (Slow Ions from an ECR ion source) will be controllable. The ability to produce a high intensity high energy projectile ion beam of the desired charge state makes the process of stripping one of the key parameters to make the project FISIC a success. This requires that the stripper stays stable and survives the impact of the incident ions with a very high repetition rate over an extended period of time. First numerical simulations of the interaction of an oxygen beam with a simple Al stripper target (see Fig. 1) are reported. These calculations are the first step towards designing a viable stripper system for the FISIC experiments.

In this contribution we present numerical simulations of the Richtmyer–Meshkov (RM) instability growth in solids, using a plane shock driven by an intense ion beam. The plane shock is generated using the Mach reflection technique [1]. Fig. 1 shows the position of the shock front at t = 500 ns that is propagating from the right to the left. It is seen that the shock is close to the Cu–Al boundary, but is still in the Cu region. The shock pressure is around 55 GPa and is generated by a beam intensity of 5 × 10 per bunch. The temperature in the shock heated Cu is about 900 K so that the material is in solid state and possesses solid const itutive properties.