Journal of Siberian Federal University-Mathematics & Physics最新文献_第5页

Design of a Narrowband Filter for Implementing the Undersamping Method in Terahertz Time-Domain Spectrometers 实现太赫兹时域光谱仪欠采样方法的窄带滤波器设计

IF 0.4

Journal of Siberian Federal University-Mathematics & Physics Pub Date : 2022-04-15 DOI: 10.25205/2541-9447-2022-17-1-78-92

A. Rybak, S. Kuznetsov, A. V. Arzhannikov, N. Nikolaev

引用次数: 0

Optimization of Parameters of Laser Cladding of the Powder Based on Nickel-Aluminium System 基于镍铝体系的粉末激光熔覆工艺参数优化

IF 0.4

Journal of Siberian Federal University-Mathematics & Physics Pub Date : 2022-04-15 DOI: 10.25205/2541-9447-2022-17-1-65-77

M. Gulov

{"title":"Optimization of Parameters of Laser Cladding of the Powder Based on Nickel-Aluminium System","authors":"M. Gulov","doi":"10.25205/2541-9447-2022-17-1-65-77","DOIUrl":"https://doi.org/10.25205/2541-9447-2022-17-1-65-77","url":null,"abstract":"In this work, the parameters of laser cladding were optimized to obtain a high-quality single track. Nickel aluminide powder (Ni3Al) – PN85Yu15 was used as the surfacing material. 60 samples were obtained, deposited at various pa rameters of power, scanning speed, position of the focus of the laser beam relative to the surface of the powder layer. The geometric characteristics of the obtained single tracks were measured, graphs of their dependence on the scanning speed were plotted. It was found that the sizes of single tracks decrease with increasing speed. An increase in the power of laser radiation leads to an increase in width and height of the track, as well as the depth of penetration of the substrate. The dependence of the geometric characteristics of the tracks on the temperature of the melting pool has been investigated. The microhardness of the obtained samples was also measured, and a weakly expressed dependence of the microhardness on the laser scanning speed was found. It was found that the microhardness of the obtained samples correlates with the amount of energy imparted to the powder layer and the temperature of the melting pool. It was also found that the set of experimental data is described in generalized spatial and energy coordinates by a linear dependence.","PeriodicalId":43965,"journal":{"name":"Journal of Siberian Federal University-Mathematics & Physics","volume":"17 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87785116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Flow of Ethanol into a Medium with Varying Degrees of Rarefaction 乙醇在不同稀薄度介质中的流动

IF 0.4

Journal of Siberian Federal University-Mathematics & Physics Pub Date : 2022-04-15 DOI: 10.25205/2541-9447-2022-17-1-47-64

A. S. Yaskin, A. Zarvin, V. Kalyada, K. Dubrovin, V. E. Khudozhitkov

{"title":"Flow of Ethanol into a Medium with Varying Degrees of Rarefaction","authors":"A. S. Yaskin, A. Zarvin, V. Kalyada, K. Dubrovin, V. E. Khudozhitkov","doi":"10.25205/2541-9447-2022-17-1-47-64","DOIUrl":"https://doi.org/10.25205/2541-9447-2022-17-1-47-64","url":null,"abstract":"Experimental results of observation of ethanol microjets flowing into a highly rarefied medium (vacuum) through a nozzle are presented. The investigation of the outflow process was carried out both horizontally and vertically in the direction of gravity, when the liquid was expelled from the source. The condition of keeping constant the residual background pressure in the vacuum chamber is much lower than the saturated vapour pressure of the working liquid at a given temperature of the blast. The possibility of simulation of complex processes of the flow of micro-liquids in a space with a given rarefied atmosphere on a compact vacuum gas-dynamic test bench is shown. It is found that the continuous efflux from a thin capillary or a hole of small diameter into a vacuum or a strongly rarefied gaseous medium differs significantly from the well-studied modes of efflux into a dense gaseous medium, as well as from the pulse modes of efflux into a vacuum. The paper describes the main features of the flow and the conditions of the instability emergence. It is shown that the long-term flow of a liquid microjet in a vacuum has a high degree of surface instability, with a large number of sudden changes in direction, structure and observed density. An explanation for the causes of microjet failure, caused mainly by a combination of capillary instability and intense evaporation of superheated liquid from the surface of the jet, is proposed. The formation of surface gas caverns causing explosive collapse of the microjet with ejection of vapor-liquid droplets is established.","PeriodicalId":43965,"journal":{"name":"Journal of Siberian Federal University-Mathematics & Physics","volume":"59 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85625300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The High Voltage Source for the ELV-15 Accelerator ELV-15加速器的高压源

IF 0.4

Journal of Siberian Federal University-Mathematics & Physics Pub Date : 2022-04-14 DOI: 10.25205/2541-9447-2022-17-1-23-33

N. Kuksanov, D. Vorobev, R. Salimov, S. Fadeev

引用次数: 1

Investigation of Transverse Instability of a High-Current Relativistic Electron Beam in a Linear Induction Accelerator 直线感应加速器中大电流相对论电子束横向不稳定性的研究

IF 0.4

Journal of Siberian Federal University-Mathematics & Physics Pub Date : 2022-04-14 DOI: 10.25205/2541-9447-2022-17-1-5-22

E. Sandalov, S. Sinitsky, D. I. Skovorodin, D. Nikiforov, P. Logachev, P. Bak, K. Zhivankov, E. Kenzhebulatov, A. Petrenko, O. Nikitin, A. Akhmetov, R. V. Protas, S. Khrenkov, I. A. Zhuravlev, I. V. Penzin, A. Don

{"title":"Investigation of Transverse Instability of a High-Current Relativistic Electron Beam in a Linear Induction Accelerator","authors":"E. Sandalov, S. Sinitsky, D. I. Skovorodin, D. Nikiforov, P. Logachev, P. Bak, K. Zhivankov, E. Kenzhebulatov, A. Petrenko, O. Nikitin, A. Akhmetov, R. V. Protas, S. Khrenkov, I. A. Zhuravlev, I. V. Penzin, A. Don","doi":"10.25205/2541-9447-2022-17-1-5-22","DOIUrl":"https://doi.org/10.25205/2541-9447-2022-17-1-5-22","url":null,"abstract":"The article presents the results of studies on the transverse instability of a high-current relativistic electron beam developing in a linear induction accelerator LIA for 5 MeV electron energy, which is created at the BINP SB RAS together with RFNC VNIITF. These results were obtained using a software package that makes it possible to simulate the dynamics of the instability development, as well as to calculate the increment of this instability averaged over the accelerator length. The package consists of four main parts. The first of them, made on the base of a three-dimensional model of the accelerating module electrodynamic system of the LIA, allows calculating the main characteristics of electromagnetic dipole modes of such a module, the second and third parts are designed to find three-dimensional accelerating electric and focusing magnetic fields, respectively. In the last part of the package, a system of ordinary differential equations is solved that describes both the motion of beam macroparticles in electric and magnetic fields, including the eigenmode fields, and the excitation of the mode fields by the electron beam. The adequacy of the physical models used in the software package was tested by comparing the spectra of field oscillations in the accelerator modules obtained in calculations and recorded in the experiment. On the base of the data obtained, the main regularities of the transverse beam instability development in the frequency range ∆f = 0.3–1.1 GHz were revealed, and possible methods for suppressing this instability in the LIA were proposed.","PeriodicalId":43965,"journal":{"name":"Journal of Siberian Federal University-Mathematics & Physics","volume":"148 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88651410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Investigation of Long-Term Stability of Single-Photon Quantum Key Distribution in a Polarization Coding Scheme 偏振编码方案中单光子量子密钥分配的长期稳定性研究

IF 0.4

Journal of Siberian Federal University-Mathematics & Physics Pub Date : 2022-01-12 DOI: 10.25205/2541-9447-2021-16-2-81-93

A. V. Kolyako, A. Pleshkov, D. Tretyakov, V. Entin, I. Ryabtsev, I. Neizvestny

引用次数: 0

Development of Disturbances in the Supersonic Boundary Layer under Helium Injection from the Surface 表面氦注入下超音速边界层扰动的发展

IF 0.4

Journal of Siberian Federal University-Mathematics & Physics Pub Date : 2022-01-11 DOI: 10.25205/2541-9447-2021-16-2-41-47

V. Lysenko, B. Smorodsky, A. Kosinov

引用次数: 0

Effect of an Electric Field on an Optical Breakdown in the Air Stream 电场对气流中光学击穿的影响

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Journal of Siberian Federal University-Mathematics & Physics Pub Date : 2022-01-11 DOI: 10.25205/2541-9447-2021-16-2-48-58

V. Zudov, A. Tupikin

{"title":"Effect of an Electric Field on an Optical Breakdown in the Air Stream","authors":"V. Zudov, A. Tupikin","doi":"10.25205/2541-9447-2021-16-2-48-58","DOIUrl":"https://doi.org/10.25205/2541-9447-2021-16-2-48-58","url":null,"abstract":"Experimental data on the effect of an electric field on the plasma of an optical discharge in an air flow have been obtained. Two configurations of an external electric field under the action of an optical discharge on the plasma are considered. To create an electric field, flat (the field along the beam and across the flow) and ring electrodes (the field across the laser beam and along the flow) were used. It was found that there are two modes of combined discharge (optical and electrical). When the field was created symmetrically with respect to the flow axis, an electrical breakdown was observed from the nozzle exit (positively charged electrode) to the focusing point of the laser beam, while no streamers were observed in the optical discharge wake. In another case, an electric discharge is realized between flat electrodes simultaneously with optical breakdown. In a field of constant strength above 3 kV/cm, the presence of an optical discharge plasma promoted electrical breakdown of the medium. In this case, the parameters of the electrical breakdown depended on the shape of the electrodes, the polarity of the applied voltage, and the air flow rate.","PeriodicalId":43965,"journal":{"name":"Journal of Siberian Federal University-Mathematics & Physics","volume":"15 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86068084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study of Flow around a Trapezoidal Model of a Small-Sized UAV into Turbulent Wake 小型无人机进入湍流尾迹的梯形模型绕流研究

IF 0.4

Journal of Siberian Federal University-Mathematics & Physics Pub Date : 2022-01-11 DOI: 10.25205/2541-9447-2021-16-2-14-28

A. Pavlenko, A. V. Bykov, B. Zanin, M. Katasonov

{"title":"Study of Flow around a Trapezoidal Model of a Small-Sized UAV into Turbulent Wake","authors":"A. Pavlenko, A. V. Bykov, B. Zanin, M. Katasonov","doi":"10.25205/2541-9447-2021-16-2-14-28","DOIUrl":"https://doi.org/10.25205/2541-9447-2021-16-2-14-28","url":null,"abstract":"Investigations of the structure of the flow near the surface of a trapezoidal model of a small unmanned aerial vehicle were carried out when it enters a narrow turbulent wake. All experimental data were obtained in a wind tunnel at subsonic flow velocities. A feature of the work was that the study of the flow around the model was carried out at full-scale (flight) Reynolds numbers. Using the soot-oily visualization method, data on the features of the flow around the model were obtained, taking into account such factors as the angle of attack, the presence and absence of a source of external disturbances that generated a turbulent wake. The experiments were carried out in two flow regimes: at a zero angle of attack, when there are local separation bubbles on the wing, and at a large (supercritical) angle of attack of 18 degrees, when there is a global stall of the flow from the leading edge. It was shown that the turbulent wake has a significant effect on the nature of the flow near the model surface in both cases. Local separation bubbles gradually decrease in size with a decrease in the distance between the sources of disturbances and the wing. Large-scale vortices significantly decrease in geometrical dimensions and shift towards the side edges in the event of a global stall of the flow, thereby increasing the region of the attached flow on the model surface.","PeriodicalId":43965,"journal":{"name":"Journal of Siberian Federal University-Mathematics & Physics","volume":"43 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87548584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Specific Features of Flow on Compression Surfaces of a Convergent Air Intake 收敛式进气口压缩面流动特性研究

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Journal of Siberian Federal University-Mathematics & Physics Pub Date : 2022-01-11 DOI: 10.25205/2541-9447-2021-16-2-29-40

S. A. Akinin, A. Starov

引用次数: 0