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Accepted papers
Visualization of surface flow with different roughness coefficients
Win Thu, D. V. Ilin, N. M. Skornyakova
Accepted: 2021-07-30
Abstract
The work purpose is to determine the impact of a rough surface on the airflow around it, depending on the degree of the surface roughness.
The experimental research of the process of air stream flowing around samples of flat and rough surfaces has been performed. The experimental results have been compared with theoretical ones obtained by executing a simulation of the considered process which is based on RANS equations.
Investigation of the jet liquid flows structure by multicolor Particle Image Velocimetry
S. S. Usmanova, A. V. Kuchmenko, N. M. Skornyakova, M. V. Sapronov
Accepted: 2021-07-30
Abstract
The work aim was to find out the possibility of using multicolor particle image velocimetry for the diagnosis of jet liquid flows. The main difference between this method and particle image velocimetry is that three laser planes of different wavelengths located at a short distance from each other are used as probing radiation. This modification allows obtaining information about the flow structure simultaneously in three different planes. A jet liquid stream from a sprayer has been considered as a research object. As a result, a laboratory setup was assembled and a series of experiments were carried out. The paper presents examples of experimental images, the processing result, describes its algorithm, and also estimates the accuracy of the data obtained.
Dendrograms in regional socio-economic analysis: interpretation and verification
V.I. Blanutsa
Accepted: 2021-07-25
Abstract
Interest in regional socio-economic analysis has grown in the last decade. Various tools are used to visualize its results. One of them is the dendrogram. However, in world science there is no generalization of the experience of using dendrograms to display the sequence of combining regions into socio-economic clusters. Therefore, the goal of our study was to generalize such experience with an emphasis on the interpretation and verification of dendrograms. Based on eight bibliographic databases using a special semantic search algorithm, more than eighty journal articles published around the world in the last two decades have been identified. These articles contain one hundred and thirty dendrograms. Their analysis showed that the main purpose of tree diagrams is to fix the sequence of combining regions into clusters and to substantiate the number of clusters. Two new types of interpretation of dendrograms are proposed – the allocation of nuclei in clusters and the determination of the level of socio-economic cohesion of clusters. To test the validity of determining the number of clusters, the author's algorithm for identifying the optimal clustering option is proposed, based on the idea of the complexity of the tree in graph theory. The ten main problems of visualizing the results of regional socio-economic analysis using dendrograms are listed.
Determination of the parameters of a vortex ring with an air core in a liquid by computer processing of video images
E.A. Chashnikov, V.V. Nikulin
Accepted: 2021-07-23
Abstract
The aim of this work is to study vortex rings with high buoyancy. Due to the vertical upward injection of a pulsed air jet into water, an air ring is formed, the shape of which is close to a torus, but not stationary in time and inhomogeneous in space. To compare experiments with theory, it is necessary to know the average geometric sizes of the ring. An autonomous method for processing vortex ring’s video images obtained from two mutually perpendicular directions: from the side and from above, has been developed in the Matlab. The proposed technique can be ported to other programming languages and allows to measure dependences of the distance travelled, the core mean radius, the core cross-section mean radius and core volume on time by defining the visual boundaries of the ring from both directions. The technique does not depend on the background uniformity. Necessary condition is a leap in the intensity of the black-and-white image between the background and the entire ring boundary. Visualization was carried out by the shadow image method. The threshold contrast leap in our case was equal to 4. Processing of a colour image is possible after conversion to black and white.
Investigation of artificially induced bag-breakup fragmentation of water surface with optical methods
D.A. Sergeev, A.A. Kandaurov, Yu.I. Troitskaya
Accepted: 2021-07-23
Abstract
Present paper devoted to the investigations with optical methods of the processes of artificially induced bag-breakup type of spray formation phenomenon within wind-wave interaction. Experiments were carried out on the Thermostratified Wind-Wave Tank (TSWiWaT) of the IAP RAS. High-speed video filming with the shadow imaging method demonstrated that it was possible to artificially reproduce all the main stages of this phenomenon, which are also observed for the sporadically occurred ones: inflation of a thin membrane surrounded by a thicker rim, rupture of the membrane leading to the formation of small droplets, fragmentation of the rim with the formation of large droplets. Special processing of the images allowed us to estimate typical lifetimes and sizes of membrane for artificial bag-breakup events which turned out to be close to the same parameters for sporadically occurred ones.
COMPUTER VISUALIZATION OF TURBULENT PARAMETER FIELDS IN A ROUND JET BASED ON LASER DOPPLER AND FIBER OPTICS MEASUREMENTS
V.I. Smirnov
Accepted: 2021-07-23
Abstract
Based on local laser Doppler and fiber-optic anemometric (LDA and FOA) measurements, a computer visualization of the fields of turbulence parameters in an axisymmetric submerged fluid jet flow at Reynolds number 15,000 was performed by the parametric identification method. The scheme of the FOA measurement, the instrument function of the FOA and the problem of its elimination are considered. Formulas for calculating the first four moments of the two-dimensional probability density of turbulent pulsations of the local velocity are given, taking into account instrument distortions. Simple parametric models are proposed to describe the fields of turbulence parameters in an axisymmetric jet flow. On this basis, the patterns of the average velocity field, the turbulence intensity field, and the shear stress field are reconstructed. Estimates of the coefficients of asymmetry and kurtosis of the probability density function of the local velocity are obtained based on calculations of the higher statistical moments of turbulent pulsations of the local velocity. The results of measurements of the coefficients of asymmetry and kurtosis indicate deviations of the velocity pulsation statistics from the normal law, even for axial regions at long distances from the nozzle. This may be due to the presence of coherent vortex structures in the flow and intermittency. In the peripheral areas, return flows can also affect, caused by the peculiarities of the geometry of the cuvette and its final dimensions. The presented results of quantitative visualization allow us to calculate the energy dissipation and other integral characteristics of the flow.
Investigation Of Thermal Inhomogeneities In Liquid Using Of A Laser Sheet Refractograms
K.M. Lapitskiy, I.L. Raskovskaya, I.A. Lapitskaya, E.B. Badamshina
Accepted: 2021-07-19
Abstract
The possibility of the computer-laser refraction method application for investigation thermal inhomogeneities in liquids is demonstrated. A technique for direct task solution concerning refraction of a sheet laser sheet beam on inhomogeneities of different structures is considered. The results of modeling the refraction of laser radiation applying the developed numerical algorithm for constructing the trajectories of geometric-optical rays in an inhomogeneous medium are presented. An experimental technique for reconstructing the temperature profile of inhomogeneity in liquid from refractograms is implemented.
Study of the cold test effect on microcirculation by video capillaroscopy
M.V. , A.S. Machikhin, E.D. Lovchikova, D.D. Khokhlov, I.A. Balandin, A.V. Potemkin, V.S. Galanova, I.V. Danilycheva, I.V. Dorofeeva
Accepted: 2021-07-19
Abstract
The cold stress is one of the main functional tests in the study of the microvascular bed of the skin. An important task is to automate visualization of the capillary network and measurement of microcirculation parameters directly in the local area of inflammation. In this paper, we describe a system developed for non-invasive visualization of the microcirculation and the processing of such images in order to determine the morphological parameters of the capillary network and their changes under external conditions. Proposed approach provides high-quality visualization of the skin microvessels and allows obtaining reliable information about the capillary map. The results of experimental studies are presented. Obtained data may be used for the development of the new methods for detecting hidden hemodynamic disorders and diagnostics of various diseases.
High-Speed Shadowgraphy of the Interaction of an Oblique Shock Wave in a Channel with a Surface Sliding Discharge
I.V. Mursenkova, Yu. Liao, P.Yu. Ulanov, L. Shi
Accepted: 2021-07-19
Abstract
The spatial structure of a supersonic flow with an oblique shock wave is studied experimentally during nanosecond surface sliding discharge initiation in a discharge chamber of a shock tube. An inclined shock wave was generated in a supersonic flow around a small obstacle on the lower wall of the channel. A surface sliding discharge was initiated on the upper wall of the discharge chamber directly in the region of interaction of the inclined shock wave with the boundary layer. High-speed shadowgraphy visualization of the flow field was carried out with a frequency of up to 150,000 frames per second at Mach numbers of flows up to 1.70. The discharge characteristics was recorded at different stages of flow and showed dependence on the type of interaction of the oblique shock wave with the boundary layer. It is established that the shock wave dynamics from the discharge depends on the discharge mode and the flow Mach number. According to the digital shadowgraph image processing, the shock waves generated by the discharge affects the shock-wave structure of the flow during ~ 100 μs.
Methods for panoramic visualization and digital analysis of thermophysical flow fields. A review.
I.A. Znamenskaya
Accepted: 2021-07-17
Abstract
The paper presents a review of modern methods in the registration, processing, and analysis of dynamic processes in liquids, gases, plasmas, multiphase media, which are realized in researches and technology. The review author observes both the physical fundamentals of flow visualization and the basics of the modern technologies for digital processing of recorded flow images. A brief analysis of the of the panoramic visualization methods progress history covers a period of one and a half centuries. In the works of the last decade, the focus is on the methods of computer processing, tools, technologies for analyzing and recognizing of panoramic thermophysical fields, which make it possible to obtain quantitative information about flows. The review contains an analysis of publications describing the main modern methods of visualization of flows: methods based on the phenomenon of refraction; electroluminescence; on digital tracing (particle image velocimetry), visualization of surface flows (PSP and TSP coatings, liquid crystals; oil coatings). Particular attention is paid to methods using cross-correlation image processing algorithms. Those are: digital tracing (PIV), shadow background method (BOS), seedless shadow methods, thermographic PIV, velocity measurement in viscous coatings, micro, tomographic modifications of PIV, etc. The actual problem of digital data analyzing in a panoramic experiment is touched upon - the problem of big data. Examples of the machine learning use in the analysis of big data sets of shadow surveys are given. Some examples of numerical simulation data visualization (simulation of experimental flowfields) are considered.
Analysis and Visualization of the Computational Experiments Results on the Comparative Assessment of OpenFOAM Solvers Accuracy for a Rarefaction Wave Problem
A.E. Bondarev, A.E. Kuvshinnikov
Accepted: 2021-07-14
Abstract
The article is devoted to the analysis and visualization of the generalized computational experiment results on the comparative analysis of the accuracy for a group of open software package OpenFOAM solvers. The basic problem here is the classical problem of the rarefaction wave formation in a flow. This problem has an exact solution which we use as etalon. The generalized computational experiment makes it possible to carry out parametric studies in a grid partition of the region in the space of defining parameters. The construction of a generalized computational experiment is based on the synthesis of mathematical modeling, parallel technologies and visual analytics. As a rule, the results obtained in such an experiment are multidimensional data, on the basis of which the objective functional is constructed, which is the main object of interest of the researcher. In this case, the defining parameters are the input stream Mach number and the flow deflection angle. The deviation from the exact solution calculated in the L1 and L2 norms is considered in the role of the objective functional. For each solver, a parametric problem is solved by varying the Mach number and flow deflection angle. The results obtained represent the dependence of the objective functional on the defining parameters for each solver. The results are presented in visual form as surfaces and in analytical form as polynomials.
Visualization of the efficiency processes management and University' HR-potential evaluation
V.D. Kolychev, N.A. Budanov
Accepted: 2021-07-11
Abstract
The article is devoted to the development and application of a set of visual analyt-ical models used in the management of performance based on key indicators and the assessment of the University's human resources potential using integrated in-formation and analytical tools. The relevance of the development and application of visual analytics methods is aimed at improving the efficiency of management decision-making, strategic planning and assessment of the potential for growth and development. The need to develop methods of visual analytics in the field of per-formance management is due to the current reconfiguration of the functioning of large-scale competitive high-tech enterprises, focused primarily on improved goal-setting technology and the use of modern methods of analyzing human resources. The article presents a set of visual models used for a comprehensive analysis and evaluation of the effectiveness of the organization, based on the use of a set of ge-ometric modeling tools that allow you to use modern computer tools to demon-strate methods of making managerial decisions.
Recovery of Particle Concentration Fields by Two-Phase Flow Visualization around Bodies
A.A. Zhelebovskiy, A.A. Mochalov, A.Yu. Varaksin
Accepted: 2021-07-01
Abstract
Measurement of the fields of particle concentration is one of the main task in research area of the two-phase flows around bodies in ‘gas – solid particles’ case. The paper considers the reconstruction of the concentration fields of solid particles by identifying their images. An experimental setup scheme for analysis of the structure of downward two-phase flow is presented. The main parameters of the experimental setup are as follows: geometry of the working area, air flow velocity, air flow rate, mass flow rate of particles. An optical monochrome setup for recording fast processes is briefly described. A method for processing experimental images based on the Canny edge detector is proposed. The processing algorithm for the experimental images was tested on glass microspheres used as a dispersed phase. The original image and a size distribution histogram for microstructures are presented. Examples of individual images of microspheres in a flow are considered for data validation. The experimental determination of the particle concentration fields in the downward flow and in the vicinity of the streamlined body are presented.
The Virtual Reconstruction of Historical and Cultural Heritage Monuments of the Vodyansky Settlement
I.A. Romanova, N.M. Poluboyarova
Accepted: 2021-07-01
Abstract
The preservation and restoration of historical memorials play very important roles in the formation of a holistic view of material culture and technology level in different society development periods. But material reconstruction of some memorials cannot be realized due to different reasons. In such cases, modern 3D technologies provide a wide range of modeling tools.
In this paper we give an example of virtual reconstruction of the cathedral mosque of the Vodyanskoe gorodishche (Vodyansky settlement) using terrain map for building a landscape. We also use the materials of archaeological excavations to create plausible textures for minaret and portal decoration. The modeling is based on reliable data from archaeological reports and on probabilistic data based on the architectural traditions of the region in the same period.
The virtual reconstruction was implemented via Blender, an open-source 3D computer graphics software
This work was supported by the Ministry of Education and Science of Russia (the project “Development of Virtual 3D Reconstruction of Historical Objects Technique”, scientific theme code 2019-0920, project number in the research management system FZUU-0633-2020-0004).
Registration of displacement and visualization of the deformation field of a cylindrical shell under its shock-wave loading
S.I. Gerasimov, K.V. Totyshev, N.A. Trepalov, R.V. Gerasimova
Accepted: 2021-07-01
Abstract
In this paper, the possibility of registering elastic deformations and vibrations of the barrel of a light-gas gun based on high-speed video recording is demonstrated, and the subsequent processing of the obtained images by a cross-correlation algorithm is carried out. The use of high-speed video recording of the cylindrical shell surface and cross-correlation analysis of the obtained images made it possible to determine the space-time dependences of the movement of the recorded surface and to visualize the deformation field. This possibility is demonstrated by the example of high-speed video recording of a fragment of the barrel of a light-gas gun LGP-5,6 in the process of firing. Vibrations of the barrel in the vertical and horizontal directions were recorded, the maximum amplitude value of which was 5 mm. The field of longitudinal elastic deformations of the barrel caused by the passage of the striker through the barrel channel is visualized.
Stand for Remote Development of a Display Visualization System for Civil Aircraft Cockpit
S.V. Andreev, E.Yu. Denisov, I.G. Ryzhova, A.G. Voloboy
Accepted: 2021-06-27
Abstract
The paper presents the original development of the stand for remote creation and debugging of the visualization system for the display of a civil aircraft cockpit. Any visualization system implies the presence of a person for whom it is ultimately intended. Naturally, such presence is necessary for the process of creating and testing the system. However, in the context of the COVID-19 pandemic, access to the premises of scientific institutions is limited. The situation is further complicated by the fact that the development of on-board software must take into account the specifics and be carried out on the target on-board equipment. Therefore, we designed and built a stand which provides remote secure access to the target platform, its remote control and makes possible to see the results of its work. We managed to avoid costly solutions and use a regular desktop PC as an auxiliary control computer. As a result the process of developing a visualization system for the cockpit display is not interrupted even when access to the target platform equipment is restricted.
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