Oleg Penyazkov

Oleg Penyazkov
National Academy of Sciences of Belarus | NAS B · Physics and Chemistry of Nonequilibrium Media

Professor

About

163
Publications
8,631
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831
Citations
Citations since 2017
54 Research Items
545 Citations
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100

Publications

Publications (163)
Article
Full-text available
Flame acceleration (FA) and the deflagration-to-detonation transition (DDT) are among the most interesting and exciting phenomena in the field of combustion and explosion of gases. From both practical and theoretical points of view, it is important to understand the basic laws governing these phenomena as well as the physical and/or chemical mechan...
Article
Consideration has been given to the influence of additives of aluminum nanoparticles to mixtures of nanostructured silicon with a solid-phase oxidant on the characteristics of their high-velocity (detonation) combustion. The thermodynamic characteristics of combustion of the systems “aluminum–silicon–oxygen” and “aluminum– silicon–ammonium perchlor...
Article
This paper is devoted to investigating the dynamics of propagation of a combustion wave in a small-size pulse detonation combustor with a length of less than 0.5 m operating on heptane and Jet A-1 propellant. A link has been established between the combustion wave propagation velocity and the pulse detonation combustor thrust and the ratio of the c...
Conference Paper
В работе произведена оценка распространения волны горения в малогабаритной детонационной установке реактивного типа при сжигании смесей «гептан-воздух-кислород» и реактивного топлива «Jet A1-воздух-кислород» с учетом изменения концентраций компонентов и отношения кислорода к воздуху в смеси в диапазоне [02/воздух] < 1. Показано, что характер горени...
Article
Full-text available
Gaseous detonation propagation in a thin channel with regularly spaced cylindrical obstacles was investigated experimentally and numerically. The wave propagation with substantial velocity deficits is observed and the details of its propagation mechanism are described based on experimental measurements of the luminosity and pressure and on three-di...
Article
One of the criteria for the development of high-energy processes is the large specific surface area of the solid component of composites. Therefore, the maximum preservation of its nanostructured skeleton when separating the porous layer from the monocrystal substrate is relevant. Based on the analysis of the quality of the porous layer under vario...
Article
Full-text available
An absorption spectroscopy method is proposed for estimating hydroxyl concentration behind the refl ected shock wave front without lasers and high-resolution spectrometers. The scheme of the method realization is shown, and the possibility of its usage in experiments with shock tubes is demonstrated. Temporal profi les of hydroxyl concentration are o...
Article
Full-text available
Experiments of n-decane/air self-ignition at the temperature range 600–800 K were carried out by rapid compression machine. It allowed obtaining temperature-concentration limits of transition from single-stage to two-stage ignition. High-speed video recording has let established that hot stage ignition always initiates near the piston surface or qu...
Chapter
Innovative binary nickel membranes for hydrogen separation were developed. They proved their competitive ability in comparison with traditional palladium and palladium–nickel membranes. Moreover, it’s necessary to take into account the simplicity and low cost of their technology, low material consumption against the traditional one. Developed nicke...
Article
The physical mechanism of detonation combustion of nanostructured silicon with a solid-phase oxidant at a velocity of the combustion front of 1000–3000 m/s has been proposed. Thermodynamic characteristics of combustion of model solid-phase mixtures "silicon–ammonium perchlorate" with different equivalent ratios of their components have been calcula...
Conference Paper
The ability of porous silicon to actively participate in oxidative reactions leading to combustion and explosion when interacting with reagents in the pores was established about twenty years ago [1] but because of the high propagation velocities of these physicochemical transformations (102-103 m/s), it was di©cult to understand their mechanisms.
Conference Paper
Numerous studies have demonstrated the potential use of porous silicon (pSi) as an energetic material. However, there are a number of dificulties in such an application of nanostructured silicon. Here are two of the most serious dificulties.
Conference Paper
This work is devoted to the study of the dynamics of combustion wave propagation in oxygen-enriched mixtures of n-heptane with air and jet fuel "Jet A-1" in a small-size pulsed detonation combustor (PDC) with a diameter of 20 mm and a length less than 1 m. Experiments are carried out after the PDC reaches a stationary thermal regime when changing t...
Conference Paper
Currently, various groups of scientists are investigating the possibility of using nanostructured porous silicon as promising solid fuels (or additives to composite solid fuels) and as miniature energy sources for microelectromechanical systems. The results presented in the paper demonstrate the prospects of the proposed novations aimed at increasi...
Article
An analysis has been made of the influence of the excitation of internal degrees of freedom of molecules on the refractive index (n – 1) under the conditions of high thermal nonequilibrium using the problem on relaxation of molecular nitrogen and oxygen behind the front of a strong shock wave as an example. It has been shown that the processes of v...
Article
The spontaneous combustion of the coal microparticles of fractions 1–20 μm and 20–32 μm in an air atmosphere and the inflammation of the coal microparticles of fraction 20–32 μm in a methane–air mixture at temperatures of 700–1100 K were investigated with the use of a rapid compression machine. A contactless measurement of the temperature of the co...
Article
The three-dimensional structure of an accelerating flame front makes it very difficult to visualize. Most experimental studies that provided a visualization of flame acceleration and deflagration-to-detonation transition (DDT) events were done in rectangular tubes using the shadow technique. Qualitative information obtained by these optical methods...
Article
Full-text available
The aim of this work was to study the dynamics of deflagration-to-detonation transition (DDT) following flame acceleration in a cylindrical tube. We combined high-speed video recordings of self-luminescence and traditional local flow measurements to study the DDT process in a stoichiometric acetylene–oxygen mixture with argon dilution and nitrogen...
Conference Paper
The results of experiments on combustion of porous silicon (pSi) layers with a thickness ranging from 19 to 135 pm at oxygen pressure up to 33 bar and spark initiation of the process are presented, as well as the possible modes of pSi combustion in oxygen are indicated.
Conference Paper
The dynamics of the thrust of a jet-type pulse detonation combustor (PDC) operating on heptane/air mixtures enriched in oxygen is studied. It has been established that with simultaneous enrichment of the mixture in fuel and reduction in the oxygen-to-air equivalence ratio, the thrust characteristic of the PDC deteriorates significantly: an increase...
Conference Paper
The processes of pSi ignition and combustion in oxygen are described. When spark ignition in the porous layer releases the Joule heat, it leads to a significant heating-up of the breakdown region.
Conference Paper
The results of experimental research of deflagration-to-detonation transition (DDT) in stoichiometric mixtures of acetylene-oxygen diluted by 70% argon or 60% nitrogen in round smooth tube with diameter of 0.04 m in the mode of low-energy initiation of combustion by a spark discharge (0.8 mJ) are presented. Simultaneous registration of shock wave p...
Article
An algorithm for the development of heat pipes involving the choice of the working fluid, materials for the casing and wick, and the methods of calculating the limits of heat-transmitting ability of heat pipes is suggested. This algorithm has been applied successfully for creating different types of wicks and heat pipes on the basis of which a cool...
Conference Paper
Full-text available
The ability of porous silicon (pSi) to maintain oxidation reactions that lead to combustion and explosion [1, 2] allows treating it as a component of high-energy fuels. In work [3] an explosive system is described, where at cryogenic temperatures (4.2-90 K) the interacting atoms are in contact on an atomic scale: hydrogenated porous silicon whose p...
Article
Full-text available
The content of pyrolysis products during combustion of modified ethanol in the Rapid Compression Machine (RCM) was studied. It was found that significant reduction in the ignition delay time for lean reactive mixture ( φ = 0.6) with a decrease in maximum pressure and unchanged mean rate of pressure. It indicates an increase in the burning rate of t...
Article
The physical mechanism of combustion of thin nanostructurized silicon plates in oxygen at an elevated pressure is considered. Based on the analysis of experimental data, it has been established that in combustion wave propagation over a nanostructurized silicon film, the liquid silicon droplets resulting from thermochemical destruction of etched si...
Article
Full-text available
It is known that during the process of carbon nanomaterials synthesis, gaseous products and various unknown hydrocarbons are formed. Thus, the production of carbon nanomaterials could damage the environment. A detailed analysis of all gaseous products during the pyrolysis process is needed in order to clarify the nature of the formed substances and...
Article
This paper presents a review and an analysis of the development of speckle photography from the first experiments performed at the National Physical Laboratory of Great Britain up to the present time. The possibility of diagnosing turbulent and three-dimensional flows by the speckle photography methods has been shown. The single-exposure scheme of...
Conference Paper
This paper proposes an approach of calculation of permissible heat fluxes of heat pipe. Simulation algorithms and their program realization are developed with the use of MATCAD. Permissible heat fluxes in the heat pipe are determined accounting operating conditions and properties of capillary-porous materials. This approach allows us to compare hea...
Article
The effect of hydrogen additives on the working process of a piston-type gasoline engine is studied. The indicator diagram has been built, and the operation of the piston engine on gasoline-air mixtures enriched with hydrogen in the amount of 0…20 % of the volume of air entering the engine has been analyzed. The possibility of obtaining satisfactor...
Article
The concentration of 16 polycyclic aromatic hydrocarbons (PAHs) in the gasoline combustion products emitted into the atmosphere by internal combustion engines (ICE) has been measured using the gas chromatography method. The concentrations of PAHs in the exhaust gases sampled behind a catalytic converter has been determined when the ICE operates in...
Article
Hydrogen fuel, as for now, is the most energy efficient and clean fuel for aviation engines. At present time RAM engines based on chemical burning of fuels and accelerating exhaust gases practically reached the top of their efficiency in terms of specific impulse. New schemes are under development. As it is known, complex geometry of combustion cha...
Article
Meta-stable systems are those staying in the local equilibrium state: being slightly deviated from it they return to the equilibrium, but in case deviation surpasses a critical value those systems fall down to another equilibrium state. Chemically reacting gaseous mixture provides a typical example of a meta-stable system. The paper is aimed at num...
Article
We consider the dependence of the procedural error of measurements of the temperature of an object by the photoemission method on its surface emissivity, selectivity of the spectral characteristic, and surface temperature. We present the plots for the determination of the procedural error at a temperature T = 2000 K within the range of selectivitie...
Patent
Full-text available
предложена идея изменяемого во времени электрода под подложкой, на которую идет осаждение нано-микрочастиц
Article
Full-text available
To investigate the effect of bifurcation on the induction time in cylindrical shock tubes used for chemical kinetic experiments, one should know the parameters of the bifurcation structure of a reflected shock wave. The dynamics and parameters of the shock wave bifurcation, which are caused by reflected shock wave–boundary layer interactions, are s...
Article
The physical and chemical principles of the preparation of carbon nanoparticles (fullerenes, carbon nanotubes) and their complexes, and the methods for introducing nanoparticles into metal, ceramic and polymer matrices are considered. The most important properties of some materials containing these cluster molecules are given. It is shown that the...
Article
Full-text available
Nanosize carbon fuel additions were synthesized by the action of an electric discharge on a diesel fuel. Depending on the discharge regime, variously shaped carbon particles, including planar graphitized ones, were formed in the fuel. Ignitability of the produced samples was assessed by the method of initiation of a foamed fuel sample by a lowcurre...
Article
The possibility of calibrating a photoemission pyrometer without using a standard temperaturel radiator is examined. The validity of such calibration is shown, since the calculated calibration curve agrees with that obtained with the use of a ribbon filament lamp.
Article
Results of an experimental and numerical study of the ignition of a stoichiometric methane–air mixture in the presence of coal particles of diameters 20–52 μm in the range of temperatures 850–1150 K and pressures 1.5–2.0 MPa are presented. It has been found that the particles begin to burn at a temperature of the oxidizing medium above 850 K. At a...
Chapter
The article is devoted to the studies of the shock tube roughness effect on the measurements of ignition delay times and the structure of the gas flow behind reflected shock wave. All measurements were performed on cylindrical shock tube at the density of the gas behind the reflected shock wave of 2.8 kg/m³ for the smooth and rough surface of the s...
Article
Full-text available
The results of the mathematical simulation of the coal-water fuel particle in the conditions of electric-spark discharge have been given. It has been found that the CWF particle can ignite even in a relatively low (Tg
Article
The results of probe measurements of radiation deflection angles by the method of Talbot images were used for tomographic reconstruction of the refractive index and temperature distribution in a methane-air flame of complex structure. The projection data were registered in different viewing directions by rotating the reacting gas flow forming syste...
Conference Paper
Full-text available
Experimental results and some theoretical ones are given . Problems of electrostatic deposition, and morphology of powder are discuused.
Article
Full-text available
In the article, the two-phase flow of electric arc gas heater of the linear scheme is studied. The power of the plasma torch can be varied from 200 to 1500 kW. For stabilization of the electric arc a magnetic coil is used. The operation of the plasma torch took place at overpressure in the discharge chamber. Injection of the powder was made near th...
Article
Full-text available
The addition of hydrogen to the various hydrocarbon fuels being examined as a promising method for increasing the efficiency of the engine while improving their emission characteristics. This work is dedicated to experimental investigation of the ignition delay time C3H8-H2 mixture in the air and analysis of the mechanisms responsible for the accel...
Article
Full-text available
This paper represents experimental investigation of ignition of combustible gaseous mixture with reactive particles in the rapid compression machine at temperatures 950-1200 K and pressures 1.5-2.0 MPa. The experiments were carried out with stoichiometric methane-air mixture in the presence of coal particles with size 20-32 μm. It was found that th...
Article
Full-text available
The aim of the present paper is to study detonation initiation due to focusing of a shock wave reflected inside a cone. Both numerical and experimental investigations were conducted. Comparison of results made it possible to validate the developed 3-d transient mathematical model of chemically reacting gas mixture flows incorporating hydrogen – air...
Article
Full-text available
A rapid compression machine (RCM) and a shock tube (ST) have been employed to study ignition delay times of homogeneous methane/air mixtures at intermediate-to-high temperatures. Both facilities allow measurements to be made at temperatures of 900–2000 K, at pressures of 0.38–2.23 MPa, and at equivalence ratios of 0.5, 1.0, and 2.0. In ST experimen...
Article
The dependence of photon energy from energy of photoelectron is base of photoemission radiation analysis. In such photoemission measurements except current of photocathode is always exist a reverse current from the collector of electrons to the photocathode in two-electrode sensors. There are various ways of reverse and uncontrolled current elimina...
Article
Flow visualization inside a combustion chamber of a rapid compression machine (RCM) was realized by a new technique. This method is based on observation of the movement of burning coal particles ignited during piston motion. The continuous combustion time of particles made it possible to analyze the distribution of their velocities and thereby to i...
Article
The results of experimental and theoretical investigations of the operation and a two-stage light gas magnetoplasma launcher are presented. An optical method for measuring the velocity of small bodies (2–10 mm) has been developed and used in testing a combined gas discharger for micro- and macroparticle acceleration. The experimental results are in...
Chapter
Full-text available
Evaporative cooling of droplets of an aqueous solution in the aerosol reactor is the main process leading to the formation of supersaturated solution in droplets. It is shown that the nucleation in this metastable solution, the coalescence and the Brownian diffusion of nanoparticles determines the growth and the morphology of the nanoparticles ense...
Conference Paper
Full-text available
The results of the applicability of the heat pipes as a heat sink for high-power LED lights designed for indoor lighting industrial facilities (shops, warehouses, sports complexes, etc.) are presented. Different designs of LED lights in terms of optimum thermal design, manufacturability, ease of manufacture and cost reduction are investigated. LED...
Article
The process of unsteady high-pressure hydrogen release observed on local vessel rupture is investigated experimentally. The flow structure during the formation of a supersonic free hydrogen jet is studied. The obtained data correlates well with the numerical simulation of sonic underexpanded hydrogen jet released into the atmosphere. In particular,...
Article
The paper discusses the principles of optical testing of transparent objects using the Talbot images method and its applicability to diagnostic of flames. The experimental study was performed for premixed methane-air flame formed by an axisymmetric nozzle. The local deflection angles of the probe radiation were determined from measurements of the r...
Article
Full-text available
Ignition of a stoichiometric methane—air mixture in a piston-driven setup at temperatures of 900–1200 K and pressures of 1–1.2 MPa is experimentally studied. The experiments reveal the emergence of bright points in the duct of the facility. The measurements show that luminescence in the volume appears almost immediately after the end of the compres...
Article
Full-text available
The results of thermal protection shield (TPS) testing of descent module (DM) for ExoMars vehicle in face Hall Accelerator (FHA) plasma fluxes are presented. Key parameters of plasma in a free flux and in net sections of fluxes are determined, the analysis of results of testing is carried out and recommenda-tions about their use are made.
Article
Full-text available
Приведены результаты рентгенофазового анализа продуктов низкотемпературного распылительного пиро- лиза фемтолитровых капель водных растворов хлорида никеля. Показано, что состав наночастиц, собранных на подложке-электроде, зависит от давления в реакторе и начального пересыщения раствора. Установлено, что заметные химические превращения начинаются п...
Article
Full-text available
The effect of turbulization of a hydrogen-oxygen-air mixture flow on the deflagration-to-detonation transition in a pulse combustor (PC) is studied. The parameters of operation of the PC with flame front propagation in a quiescent and strongly turbulized mixtures (Re ≫ 104) are compared. It is shown that, in case of a quiescent mixture no detonatio...
Article
Full-text available
Results of an X-ray phase analysis of the products of the low-temperature spray pyrolysis of femtoliter droplets of aqueous nickel-chloride solutions are presented. It is shown that the composition of the nanoparticles accumulated on the electrode-substrate in an aerosol reactor depends on the pressure in it and the initial supersaturation of the s...
Article
Full-text available
Text of the paper is in Russian. For reduced pressure 60–300 Torr experimental results and theoretical estimates of electrostatic deposition of femtoliter droplets, containing inside nanoparticles, from the gas stream on substrate-electrode are presented. It is shown that the corona discharge with a stream of droplets is stable in a limited range o...
Article
Results of experimental study of the process of interaction of a pulsed magnetic field and a zone of collision of two opposing compression plasma flows have been given. It has been shown that the field of the magnetic trap bounds the region of the cumulative zone due to the compression of a plasma formation resulting from the collision of the two f...
Article
This paper describes methods for obtaining of anodic alumina membranes. Gas permeability of membranes formed in oxalic acid for such gases as nitrogen, hydrogen, helium and oxygen was investigated. It is shown that that molecular diffusion of gases through membrane takes place and experimental data has good correlation with theory.