# Vol 24, No 2 (2023)

## Section 1. Computer Science, Computer Engineering and Management

### Conservative semi-Lagrangian method for continuity equation with various time steps in different parts of computational domain

Vyatkin A.V., Maltsev A.V.

#### Abstract

The system of Navier – Stokes differential equations describes gas flow near rocket nozzle. To find solution of this system in general case, scientists and engineers use numerical methods. Modern numerical methods do not allow engineers to model all features of gas flow. It happened because of sophisticated physical processes and limitations of computational hardware. So, at least where are two ways to improve it: to enlarge hardware or reduce computational complicacy. The global aim of many science investigations is to develop numerical approach with reduced computational complicacy and at the same time without loss of computational accuracy. In 1959, Aksel C. Wiin-Nielsen proposed a new and effective trajectories method for problem of numerical forecasting. In 1966, K. M. Magomedov developed similar approach (method of characteristics) for numerical modelling of space (three dimensional on space) gas flow. In 1982, O. Pironneau showed a new and effective approach for two dimensional approximation of the Navier – Stokes problem. It was based on method of characteristics also. Nowadays, these methods are called semi-Lagrangian or Eulerian – Lagrangian methods. They use Lagrangian nature of the transport process. To apply this advantage, scientists decompose each equation of Navier – Stokes system into three parts: convective part (hyperbolic type), elliptic part and part of right-hand side. Scientists use semi-Lagrangian approach to approximate the convective parts of equations. To develop and test modern algorithms from family of semi-Lagrangian methods, we use continuity equation from the system of Navier – Stokes equations. Conservative versions of semi-Lagrangian approach are based on Gauss – Ostrogradsky (divergence) theorem. It allows scientists to get conservation low (balance equation) for numerical solution in norm of L1 space. Aim of our investigation is to use different time steps in different parts of computation domain. It enables us to obtain at the same time three advantages: convergence of numerical solution to exact solution, reduction of computational complicacy, implementation of conservation low (balance equation) without weight coefficients. For this purpose we decompose computational domain into two parts (subdomains) and use different time steps in them. Main complication is design algorithm in the boundaries of computational subdomains. We use one dimensional (on space) problem to demonstrate ability of developing numerical method with described advantages. Generalization of considered approach for two- or even three-dimensional cases allows engineers to model gas flow more accurately and without artificial viscosity. It is essentially important in the parts of computational domain with high level of solution gradient.

Siberian Aerospace Journal. 2023;24(2):218-233
218-233

### Algorithm for calculation of wave numbers in a chiral metamaterial based on composite spiral elements

Dementiev A.N., Kurkin A.N., Smirnov S.V., Arseniev K.V., Zhukov A.O.

#### Abstract

Materials with various exotic electromagnetic characteristics have been extensively studied in recent decades to satisfy the growing interest in various fields, including visualization, telecommunications, energy use, and so on. As a particularly promising candidate, electromagnetic metamaterials exhibit electromagnetic properties that are inaccessible to natural materials. Due to the fact that the chiral medium (metamaterial) is a set of uniformly distributed conductive mirror-asymmetric (chiral) elements in an isotropic dielectric medium. In addition to the material from which the chiral element is made, its shape also plays an important role. That is why it is so important to study new types of chiral elements, as well as to determine the electrodynamic properties of chiral metamaterials based on them. The paper considers the solution of the problem of determining the reflection and transmission coefficients when a plane electromagnetic wave falls on a planar layer of a chiral metamaterial based on multi-pass conducting elements of the spiral type, taking into account the structural parameters of the metamaterial, which is a matrix of thin-wire ideally conducting elements in the form of N mutually orthogonal spirals. To determine the parameters of a chiral metamaterial based on composite spiral elements, the construction of a particular mathematical model of a composite element based on an arbitrary number of spiral elements in a spatial configuration, as well as a metamaterial based on a matrix of such elements, is considered. An algorithm for calculating the propagation constants of waves with circular polarizations in the specified metamaterial is proposed. From the calculations presented, it can be noted that the metastructure under study at one frequency can act as a frequency-selective protective shield that is not transparent to radiation near the main resonant frequency.

Siberian Aerospace Journal. 2023;24(2):234-246
234-246

### Development concept of inter-satellite laser communication

Kartsan I.N.

#### Abstract

The relevance of this research work is dictated, among other things, by the need to ensure higher requirements for the accuracy characteristics of the navigation field created by spacecraft of the GLONASS navigation system in order to meet the high requirements for the accuracy characteristics of navigation determinations over long intervals of autonomous operation of spacecraft currently put forward by consumers. The presented concept of development uses the latest achievements of laser and radio engineering both to increase the throughput, noise immunity of transmitting information, as well as to reduce the mass and power consumption of onboard equipment, and to conduct inter-satellite range measurements and synchronization of onboard time scales of spacecraft navigation systems, including and for linking the system time scale of space navigation systems (or the group orbital time scale) to the time scale of the State standard of time and frequency. Ensuring the accurate operation of the laser guidance system in space is considered one of the critically important tasks, since its full-scale tests on Earth are almost impossible. Key experimental and also experimental works are analyzed according to the problems of constructing optical links of inter-satellite communication.

Siberian Aerospace Journal. 2023;24(2):247-259
247-259

### Space integrated network: architectural and technical solutions justifica-tion of the ReshUCube-2 space mission

Kustov N.D., Evdokimov K.S., Shahmatov A.V.

#### Abstract

Space missions using small CubeSat-type spacecraft have become widespread. In this regard, integrated space networks are a promising direction for the development of this industry. In this paper, the architecture of such a network is proposed. It is planned that the first node of this network will be the ReshUCube-2 device.

Functional requirements and technical limitations of the described architecture were determined. Based on the requirements, a review and comparative analysis of network protocols and technologies of different levels: physical, channel, network, transport and application. As a result, a network stack is proposed that meets these requirements. The key protocols in the stack were chosen: LoRa, 802.15.4, IPv6, 6LoWPAN, RTL, TCP, UDP and CoAP. Methods of software and hardware implementation of network nodes are proposed. A test bench based on specially developed unified devices is demonstrated, on which it is proposed to work out the functions of network interaction. A test payload board for small spacecraft – nodes of the space segment is also shown.

The results obtained will be used in the development of future space missions of the Reshetnev Siberian State University. In addition, the results can be useful in the design of the Internet of Things, the Internet of vehicles and similar networks. The results of the work can also serve as a basis for future research in the field of network technologies, digital signal processing, inter-satellite interaction and space information systems.

Siberian Aerospace Journal. 2023;24(2):260-272
260-272

### On the bottom layer in groups

Senashov V.I.

#### Abstract

The question of the possibility of restoring information about a group by its lower layer, that is, by the set of its elements of prime orders, is considered. The question is classical for mathematical modeling: restoration of the missing information about the object from the part of the preserved data. A group is said to be recognizable from the bottom layer under additional conditions if it is uniquely reconstructed from the bottom layer under these conditions. A group G is said to be almost recognizable from the bottom layer under additional conditions if there exists a finite number of pairwise nonisomorphic groups satisfying these conditions, with the same bottom layer as the group G. A group G is called unrecognizable from the bottom layer under additional conditions if there is an infinite the number of pairwise non-isomorphic groups that satisfy these conditions and have the same bottom layer as the group G. Results are given on the recognition of groups by the bottom layer in various classes of groups. The concept of recognizability by the lower layer was introduced by analogy with the actively studied recognizability by spectrum, that is, by the set of orders of group elements. In this paper, we consider groups that, without a single element, coincide with their bottom layer. Examples of groups with these conditions in the classes of Abelian and non-Abelian groups are given. The properties of such groups are established. The results can be applied when encoding information in space communications.

Siberian Aerospace Journal. 2023;24(2):273-278
273-278

## Section 2. Aviation and Space Technology

### Problematic issues of application of methods of accelerated radiation testing of ECB

Avdyushkin S.A., Maximov I.A., Kochura S.G.

#### Abstract

Siberian Aerospace Journal. 2023;24(2):280-290
280-290

### Algorithm for simulation of vibration effects during track tests of aircraft and missile technology

Astakhov S.A., Biryukov V.I., Borovikov D.A.

#### Abstract

Track high-speed ground tests of products of aviation and rocket technology make it possible to experimentally confirm the aerodynamic and strength characteristics of new aircraft or their components. Experimental installation “Rocket rail track 3500”, located on the territory of the Federal State Enterprise “Scientific Test Range of Aviation Systems named after L. K. Safronov” (FKP “GkNIPAS” named after L.K. Safronov), is a complex hydro-gas-dynamic engineering structure. The main part of this installation is a rail track placed on a special concrete base, which is based on piles to eliminate the influence of viscoelastic ground vibrations. Between the rails, taking into account the profile of the track, a hydrodynamic multi-level tray is made, designed for hydraulic braking of the stored track sled. The movable rocket track sled rests on slip shoes covering the top rail head. On the track sleigh, solid propellant rocket engines and the object of study are placed. The article describes the approach to the calculation of determining the dynamic loads acting on the elastic structure of the track sled with the test object. The design is represented by a schematic spatial model of elastic beams in the form of rods, plates, pipes with equivalent mass and stiffness, interconnected by elastic links. A model of non-stationary aerodynamic forces is formulated taking into account viscosity for numerical calculations of the flow around the sled structure. Programs have been developed and modeling of the aerodynamic interaction in the case of a supersonic air flow around the structure of a rocket sled has been carried out. The results of vibrational accelerations of elements, components of the sled and the test object, depending on the speed of movement, were obtained by calculation. The forms and frequencies of natural free vibrations of the sled structure are determined, and the densities of the vibration acceleration spectra are calculated.

Siberian Aerospace Journal. 2023;24(2):291-308
291-308

### Numerical simulation of supersonic gas flow in a conical nozzlewith local plasma heating and experimental results

Voronin S.T.

#### Abstract

The results of the main theoretical calculations and some experiments on local heating of the supersonic flow of gases by an external inductor with low-temperature plasma during the ionization of gases in a ceramic, conical nozzle, carried out by means of a powerful, high-frequency, electromagnetic field, are given. Numerical calculations are based on the provisions of electromagnetic field theory based on the equations of Maxwell, NavierStokes for gas dynamics, SahaEggert for ions and electrons, which make it possible to calculate the basic parameters of the inductor and the necessary specific power for heating supersonic, multicomponent, gas flows with low-temperature plasma. A model of vortexless (laminar), supersonic, stationary gas flow was used and mathematical modeling of its movement in a conical nozzle was carried out with the aim of possibly using the effect of additional heating of the gas flow with low-temperature plasma to increase the efficiency of the liquid rocket engine.

It was found that in order to effectively heat the gas flow with low-temperature plasma in the design diameter, a conductivity of gases of at least σs ≥ 200 1/Ω·m is required for the initial temperature Ta = 2528 – 2674 оK and the frequency f = 27,12 MHz, which is not feasible even in the presence of a high concentration of impurities based on alkali metals. Therefore, a special device was developedan ionizer for the combustion chamber. The use of an ionizer allows to achieve the specified conductivity for the pressure in the combustion chamber of 15 MPa (a link to the article is given in the list of references).

Calculations indicate the possibility of effective heating with low-temperature plasma of the supersonic flow of gases in the initial volume of the conical nozzle, which is adjacent to the critical cross-section of the liquid rocket engine. This will allow in the future to significantly increase its specific impulse and thrust at the start, due to an increase in the flow rate of gases in the design section. It has also been determined that the parietal region of a conical nozzle has a significant temperature gradient in the radial direction, whereas along the symmetry axis of the conical nozzle, the temperature increase has a linear relationship.

The results of numerical simulations are qualitatively consistent with the experiments conducted in a quartz reactor cooled by water, which made it possible to use a variety of gas and gas-liquid mixtures to select fuel with the optimal composition of components. Preliminary data obtained on a working stand with a thermal power of a quartz reactor not exceeding 4 kW are given.

Siberian Aerospace Journal. 2023;24(2):309-324
309-324

### To the method of calculation of the main characteristics of promising booster electric pump units of liquid processor engines

Dubynin P.A., Tolstopyatov M.I., Zuev A.A., Chernenko V.V.

#### Abstract

The increase in the capacity of electric power sources, the use of electric motors in the systems for supplying rocket fuel components from foreign companies, the limitations on the power of classical fuel supply systemsall these conditions set a trend for studying the possibility of introducing electric drives for rocket engine power systems.

The study is devoted to the analysis of the possibility of using electric motors as a drive for the main and auxiliary pumps of liquid rocket engines. Promising developments in the field of rechargeable batteries give grounds for a mathematical justification for the use of this technical solution in order to modernize power systems, both existing rocket engines and samples under development.

The article presents a selection of patents for modern technologies for creating high-capacity batteries, an analysis of the use of technology for the use of electric motors in the international market for delivering payloads to orbits, and a rationale for the prospects of this direction in the development of rocket engines. The statistics of the causes of failures of upper stages and their correlation with units, which can be replaced by more reliable systems using electric motors, have been studied. The advantages and disadvantages of power supply systems with the use of electric drives are determined.

This study allows us to conclude that the use of electric motors in rocket engine power systems is a promising solution that improves the efficiency of the propulsion system, performance and reliability.

Siberian Aerospace Journal. 2023;24(2):325-334
325-334

### Implementation of “digital twin” technology within the thermo-elastic distortion testing of a precision carbon fiber reflector for the spacecraft antenna subsystem

Ivanov A.V.

#### Abstract

Mirror antenna subsystems (AS) with the deployable reflectors are important integral parts of the telecommunication spacecraft payloads and provide reception and transmission of the information in a given service area [1–4]. The reflector design shall provide strength and stiffness, specified radiofrequency (RF) characteristics and antenna pattern boresight error of the AS. Performance compliance shall be approved in the frame of ground experimental testing, and thermo-elastic distortion (TED) testing to assess their effect on the antenna pattern boresight error is the part of the ground testing.

This testing is hard to carry out because of the following aspects resulting in lack of the guaranteed achieved criteria to assess the test results:

considerable difference of thermal and physics behavior between carbon-fiber-reinforced polymer (CFRP) filler and epoxide component and the steep CFRP anisotropy result in increased variation of the layer strain-stress state and internal stresses which make the design behavior undefined under thermal environment;

it is almost impossible in the frame of the testing to implement and maintain the real map of the thermal fields of specified accuracy on the large-sized object due to the fact that the temperature in a giant thermal chamber is extremely varying;

in the frame of testing it is possible to carry out few optical measurements for the deformed reflector surface points which are not enough to provide the required level of confidence for geometric parametersvariation;

the test lasts 50 days and requires cost-intensive chamber exploitation, huge power consumption & operating fluid rate (liquid nitrogen), expensive equipment providing thermal modes.

Development and implementation of the cutting-edgedigital twintechnology is the effective method to address TED testing issue. The main idea of the technology is to substitute real object to be tested with digital model verified based their parameter compliance using convergence criteria. The paper presents technology block diagram, convergence criteria and correlation technique of the predicted and measured TED cases. Evaluation data of the deformed reflector effects on AS RF performances are given and demonstrate that performances comply with the specified requirements and qualify successfully thedigital twintechnology under real testing. Thedigital twinwas successfully implemented in 2019 year in JSCRESHETNEVin the frame of reflector TED testing for RF antenna subsystem with shaped antenna pattern forExpress-AMU7” spacecraft, which was launched and accepted for the flight operation in 2021.

This is the first time in the Russian space industry tests using thedigital twintechnology of a domestic reflector for RF space AS with parameters at the imported analogues level have been successfully qualified. The qualification of this technology will ensure the competition of domestic high-tech developments and will solve the problems of import substitution and increase the share of the Russian component in the global space telecommunications market.

Siberian Aerospace Journal. 2023;24(2):335-347
335-347

### Features of defining the damping function in spacecraft finite-element models

Kravchunovky A.P.

#### Abstract

Dynamic analysis of spacecraft structures is a key item in the process of structure design. For example, a launch vehicle generates the highest loads, including dynamic ones, for most spacecraft structures. Determining of damping parameters is an important component in the analysis of the structure response to mechanical loads. It is therefore very important to be aware of the damping properties of the structure. The characterization of damping is important in making accurate predictions of the frequency response of any loaded structure. The article presents some excerpts from sources devoted to the space technique design, and containing information about damping in structures. The aim of the work was to improve the accuracy of calculations using finite element models. The paper demonstrates the results of the search for a method (form) of setting the damping function in the Femap software that would provide the correct levels of the frequency response of the structure to the loads applied. A finite element model of a cantilever beam was an object of the computational experiment carried out. A frequency table obtained at the modal analysis stage prove to be useful for frequency response analysis. The only one natural frequency in spectrum is enough to implement current study. Further, damping function was set in several ways in order to identify the one that provided the most correct response for the natural frequency under study.

Siberian Aerospace Journal. 2023;24(2):348-354
348-354

### The use of cylindrical wing propellers in aviation technology

Prokhorov V.V., Oborin L.A., Melnikov V.P.

#### Abstract

In the program documents, which describe the national development goals of the Russian Federation until 2030 with a forecast until 2025, it is stated that one of the main state goals is to expand public access to safe and high-quality transport services, increase spatial connectivity and transport accessibility of territories and mobility of the population, etc. To solve the state tasks, it is proposed to use new aviation equipment generations based on cylindrical wing propellers. The article discusses the results of research and development work on several dimensions of cylindrical wing propellers. The results obtained allow us to lay the foundation for the theory and practice of operation of cylindrical wing propellers. The understanding of the role of the geometric relations of the rotor elements and the number of blades is laid. The limits of regulation of the angles of attack and deflection of the thrust vector are determined. Strength requirements have been formed for the design and rigidity of the parts of the cylindrical-shaped impeller. The solution of kinematic mechanisms for controlling the angles of attack of the blades and flaps, and the thrust vector in general, etc. was formed. A conceptual image of a two-seat aircraft using cylindrical wing propellers is proposed. Based on the conducted bench tests of a cylindrical-type winged propulsor, tactical and technical requirements for a two-seat local aircraft using these propellers were formed. Conclusions were drawn about the need for additional research and development work to study the influence of several working aircraft rotors on each other. It is stated that it is necessary to optimize the overall dimensions of the cylindrical rotors themselves, etc. It is proposed to conduct further research to determine structural solutions for promising aircraft of greater payload and capacity.

Siberian Aerospace Journal. 2023;24(2):355-363
355-363

## Section 3. Technological Processes and Materials

### Thermodynamic properties of anisotropic antiferromagnets with four-spin exchange

Aplesnin S.S., Danilenko E.G., Cheremnykh N.A., Mashkov P.P., Zhivulko A.M.

#### Abstract

Magnetic semiconductors are widely used in microelectronics, which is used to control spacecraft. The transport and electrical properties depend on the magnetic structure, which can be changed by the action of the magnetic field and controlled by the current. The magnetic structure of semiconductors with a strong spin-lattice interaction, which is reduced to a four-spin exchange interaction, is investigated. The magnetic characteristics are calculated in a classical Heisenberg model constructed from equivalent magnetic atoms forming a simple cubic and square lattice. The Hamiltonian of the system contains the exchange interaction between the nearest neighbors, the four-spin exchange, and the one-ion anisotropy of thelight axistype. The Monte Carlo method calculates the thermodynamic characteristics: the sublattice magnetization, the quadrupole parameter, the pairwise spin-spin correlation functions, the spontaneous moment at the node directed along thelight axisand in the basis plane, the internal energy, and the magnetic susceptibility. The magnetic order type was found to change from a collinear antiferromagnet (AFM) to a noncollinear (NAF) as the four-spin exchange constant increases. The dependence of the spin correlation functions on the distance has a weakly damped oscillatory character. In the AFM-NAP transition region, the near antiferromagnetic order is replaced by the ferromagnetic one, while the far antiferromagnetic order is preserved. A phase diagram of the antiferromagnetic (AFM) and non-collinear (NAF) on square and cubic lattices is constructed on the four-spin exchange-single-axis anisotropy plane. The longitudinal and transverse susceptibility of the NAF from temperature for different parameters of the four-spin exchange is calculated. The region of anisotropy and quadrupole exchange parameters in noncollinear NAF with a first-order phase transition, the sublattice magnetization jump, and the quadrupole parameter from temperature are determined. The anisotropy and four-spin exchange constants in a classical antiferromagnet with spontaneous momentum and far- and near-order parameters were found.

Siberian Aerospace Journal. 2023;24(2):366-374
366-374

### Production of blanks for flexible waveguide sections of the spacecraft by laser weld-ing

Dmitry S.V., Murygin A.V., Zlobin S.K., Gusev V.Y., Patraev E.V., Mikhnev M.M.

#### Abstract

Currently, JSCISSnamed after Academician M. F. Reshetnev is working on the development of the production of billets of flexible waveguide sections (DHW) with sections from 20´10 to 70´30, with a wall thickness of 0.1 mm made of BrB2 copper alloy. The maximum deviation of the size of the inner channel is not more than 0.1 mm. Such methods of manufacturing DHW blanks by pressure, such as rolling and drawing, take up to 20 working shifts and include a large number of cycles (from 6 to 8), require heat treatment and etching of parts after each cycle. In this regard, the task was set to reduce the complexity of the production of DHW blanks. The solution to the problem can be welding of shells from sheet blanks on a forming device, followed by the execution of a longitudinal seam. As part of the solution of the task, the calculation of the amount of energy required to melt the edges of the part was carried out, the analysis of the possibility of assembly by various welding methods for welding thin-walled shells with exact dimensions was carried out.

The analysis of the material showed that welding should be carried out in inert media. The following methods were chosen for welding the samples: arc welding in the environment of argon protective gas with a non-melting electrode, microplasma and laser welding. In the course of the work, 30 samples of 100´200 were welded, showing that 70 % of the samples are defective during arc welding and microplasma welding, while only 5 % are formed during laser welding. The following conclusions are obtained: with arc welding methods of small thicknesses, unacceptable defects occur due to the instability of the arc, whereas when using laser welding, uniform formation of the weld is observed. Metallographic studies and tensile tests were carried out on samples welded by laser welding, showing the specific strength of the weld metal at least 90 % of the strength of the base metal and the absence of defects in the cross section of the weld metal.

Siberian Aerospace Journal. 2023;24(2):375-384
375-384

### Influence of physical and chemical properties of cutting fluids on the cutting force of the cutting process

Gaifullin I.I., Plaksin A.M., Piunov V.Y.

#### Abstract

The problem of providing increased accuracy without sacrificing productivity is encountered in almost all machine-building enterprises. cutting fluids affect the entire process of blade processing: they remove heat from the surface of the cutting tool, form an additional surface between the surfaces of the cutting tool and the workpiece, and affect the juvenile surfaces of the workpiece by means of a wedging action. The positive effect of cutting fluids is achieved only if they are rationally chosen. Currently, the choice of technological environments is based on some legislative standards of the enterprise. The market for cutting fluid has a large number of brands, which makes the decision more difficult. Сutting fluids give only a qualitative assessment of their brands based on their functional actions. A similar problem of choosing a rational brand of cutting fluids was also encountered in the manufacture of the innovative «Fregat» and «Fregat-SB» accelerating units. During the processing of the structural materials previously mentioned, the impact of cutting fluids was evaluated using an experimental method. The equipment for the experiment was machining center. The methodology for the experiment included external turning at different cutting speeds and feeds of the cutting tool. Free-falling jet irrigation was chosen as the method of supplying the cutting fluids. The cutting forces were measured under the action of various cutting fluids. On the basis of the experiment, regression dependences of the physicochemical properties of cutting fluids on cutting conditions were compiled. Subsequently, according to the regression dependencies, it is possible to select the optimal brand of the cutting fluids, taking into account the cutting forces in various cutting modes.

Siberian Aerospace Journal. 2023;24(2):385-395
385-395

### Simulation model of the system for ensuring the intraclimatic characteristics of clean industrial premises of space industry enterprises

Zhuykov D.A., Nazarov V.P., Lazeev M.G., Chernenko V.V., Tolstopyatov M.I.

#### Abstract

The creation of modern products of rocket and space technology is provided at the enterprises of the space industry by a large-scale production and technological complex that unites the main production and auxiliary units, engineering, technological and operational services that perform complex tasks to improve the quality and reliability of products.

The most important operations of the technological processes of assembly and testing of spacecraft are carried out in the so-calledclean rooms” (PE), in which the concentration of aerosol dust particles is regulated by the regulatory industry documentation, as well as the parameters of the temperature and humidity regime are set. In order to control the internal climatic condition of clean rooms and control the operation of heat and power equipment for the appropriate purpose, it is proposed to develop a digital twin of a production clean room and a system for maintaining the stability of the internal climatic characteristics of this room, taking into account the ongoing technological processes and individual operations with a large amount of functionality.

As an initial model of this system, a simulation model of the object of study is considered, which is a clean room located in a typical industrial building. The boundary conditions of the model are established, the main factors of the heat and humidity state of the internal volume are determined, a method for calculating heat flows from various heat sources is developed.

Taking into account the aerodynamic characteristics of the ventilation equipment, recommendations are presented for the mathematical determination of the parameters of air flows (inflow and removal of air masses during the operation of ventilation equipment).

As a result of the development of computational methods, a closed system of implicit nonlinear equations is obtained, which is solved by numerical bisection methods with a given accuracy.

The simulation model of the state of emergency is the basic basis for constructing a digital twin of an object, the concept of which assumes that the object can be represented as a physical and virtual system. At the same time, the display and interaction of real and virtual (digital) objects makes it possible to form specific recommendations for maintaining the required parameters (temperature, humidity, flow rate), optimizing the operating modes and maintenance of a real clean production room for the assembly and testing of modern competitive spacecraft.

Siberian Aerospace Journal. 2023;24(2):396-410
396-410

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