Vol 22, No 4 (2023)
- Year: 2023
- Articles: 14
- URL: https://journals.ssau.ru/vestnik/issue/view/633
Full Issue
AIRCRAFT AND SPACE ROCKET ENGINEERING
Method of automated arrangement of devices in a spacecraft compartment taking into account connection to interface connectors of feed-through plates of an on-board cable system
Abstract
The article proposes a method for automated arrangement of on-board equipment in the spacecraft compartment, connected to external devices through sealed adapters by the on-board cable system routes. The purpose is to create a program that allows automated placing of a part of the on-board equipment in the compartment, taking into account the existing practical principles for developing instrument placement schemes, one of which is to minimize the mass of the on-board cable system. The mathematical model is described using the matrix-topological layout method in a procedural form, as well as in a numerical form for calculating the coordinates of the placement of devices and estimating the number of cycles to find the final solution. Recommendations are provided to ensure that the full range of technical requirements is taken into account in the future. An outline flowchart of the method algorithm is presented with support in the high-level Python programming language. The software implementation of the method was carried out with emulators. Testing was carried drawing on the example of a compartment of one of the advanced space vehicles. The effectiveness of the method is evaluated by comparing the number of cycles needed to obtain the result and the total time spent on the layout relative to the control data known from the job statistics.
7-24
JSC “ODK” experience in implementing digital twin technologies in the design of gas turbine engines
Abstract
The prerequisites for the formation, basic principles and approaches of the GTE design technology used in JSC “UEC” based on the concept of “digital twin” are considered. The components of the DT technology are fixed, three types of computer models included in the perimeter of the digital twin: models “as designed”, “as manufactured”, “as tested”, are considered. The necessity for constructing automated computational chains is noted and a brief description of the process is given.
25-36
Algoritms for determining the attitude position of an unmanned aerial vehicle relative to the landing platform by using computer vision
Abstract
Algorithms for determining the attitude position of an aircraft or helicopter-type unmanned aerial vehicle relative to the landing platform with special optical marks are considered. An assessment is made of the possibility of calculating the angular position, height and distance to the landing platform in real time based on image processing by a separate on-board processor combined with a digital optical camera into a single measuring unit. The results of calculating the aircraft attitude relative to the landing platform moving along a program trajectory using computer vision algorithms are presented. Simulation of the process of recognizing optical marks on a moving platform from a moving aircraft confirmed that using a processor with a program for recognizing and identifying optical marks by using computer vision and algorithms for calculating the position of the aircraft relative to landing platforms can assuredly provide reliable information about the positioning of an unmanned aerial vehicle relative to the landing platform in real time and can be used in conjunction with other navigation aids (or independently) to ensure accurate landing of unmanned aircraft.
37-51
Features of the use of directional fixed antennas of a high-speed radio link on a small spacecraft AIST-2T
Abstract
The correct installation of antenna-feeder devices on board a small spacecraft and the choice of their parameters make it possible to ensure the solution of target problems with high quality. The main problematic issues of placement of antenna-feeder devices of the on-board equipment of the radio link for the transmission of target information on the SSC “AIST-2T” and the adopted design solutions are considered.
52-58
Designing an active electronically scanned array as part of onboard equipment of a high-speed radio communication channel
Abstract
The active electronically scanned array being developed is designed to provide an all-weather high-speed radio communication channel “Spacecraft – Earth”. It is supposed to provide fast, inertia-free observation of space by swinging the antenna beam electrically, and, in fact, is a dynamic space-time filter of the spacecraft. The aim of the work is to identify the basic principles of functioning of the array as part of the spacecraft with inherent limitations in the mass-dimensional and energy characteristics of the onboard equipment and, at the same time, high requirements for the functional characteristics. This paper presents the calculation and the main results of designing an active electronically scanned array complying with the requirements for optimizing the parameters of the antenna system. To assess the effect of scanning on the phase characteristics of the chips, a nonlinear amplifier model was developed. A statistical analysis of the phase characteristics was carried out when the load resistance changed in accordance with the obtained distribution laws. When calculating the resulting directional pattern of the antenna array, destabilizing factors were taken into account in accordance with the results of the study of the prototypes of the antenna array being created. Phase errors were calculated, mainly determined by the errors of the terminal parts of the receiving paths. Measures were implemented to ensure the effect of such phase errors on the directional pattern of the array only on the far side lobes.
59-70
Methodology of delivering space parts, tools and accessories to a near Earth orbital station on the basis of the reliability factor
Abstract
The main aspects of the deployment of multi-module orbital manned stations are considered. The methodology for planning the delivery of spare parts, tools and accessories used in planning of transport operations to the International Space Station, is analyzed. It is shown that its application is related to the problem of mathematical programming with a large number of variables, which complicates the process of finding the optimal planning option in terms of economic efficiency. Transport operations to national manned orbital stations are carried out less frequently as compared to the International Space Station due to the enormous costs of spacecraft launches taking into account possible emergency situations. An approach to improving the methodology for planning the delivery of spare parts, tools and accessories for possible use on national manned orbital stations is proposed. It consists in taking into account the reliability of on-board equipment. The advantage of the improved methodology is simplification of planning transport operations without the use of mathematical programming. In addition, the improved methodology is clear, simple and can be implemented step by step.
71-77
Optimization of the parameters of a ground speed meter of low-flying aircraft based on the application of the theory of optimal filtration
Abstract
The basic principle of parametric optimization according to the criterion of minimax of variance of the resulting error of estimation of the measured parameter is considered using the example of one of the main elements of an integrated measuring system – a ground speed meter. The meter consists of a Doppler ground speed sensor (location) and an accelerometer with a longitudinal axis of sensitivity (inertial). Based on the data on their measurement errors, the coefficients of the transfer functions of each channel of the meter containing these sensors were optimized. The result of the research is a comparative analysis of the resulting accuracy of the optimized meter for the invariant and non-invariant cases, based on the obtained graphs of the frequency distribution of variances. A reasonable conclusion is made about the advantage of an invariant or non-invariant meter depending on the frequency of the signal. The Matlab R2015a software was used for calculations.
78-85
Theoretical aspects of designing the components of an aircraft onboard cable network
Abstract
The article presents theoretical foundations of designing the components of an aircraft onboard cable network, proposed as a methodology for solving the problems of designing onboard equipment. The composition of the initial and developed technical documentation for the aircraft onboard cable network is determined. The article also shows the relationship between the stages of designing the onboard cable network and the stages of designing the aircraft. The formulation of the general task of creating the components of an onboard cable network is presented as a number of particular subtasks of a lower level of complexity. The method for solving the problem is based on a number of transformations performed with the original documentation in order to develop technical documentation for the introduction of the onboard system into the complex of onboard equipment. A number of successive transformations of the proposed bundle model using the apparatus of topology and multiset theory made it possible to form a model of the components of the onboard cable network of an aircraft that gives a detailed view of its future design. The proposed scientific approach to the design of aircraft onboard cable network components created the prerequisites for minimizing the heuristic component in the process of designing aircraft onboard cable network components.
86-98
MECHANICAL ENGINEERING
Comparative analysis of turbulence model influence in numerical simulation of an experimental radial compressor stage
Abstract
The accuracy of a CFD model of a turbo-machine might depend on a number of factors: turbulence model, quality of the mesh model, boundary conditions, solver settings, consideration of secondary geometric factors, etc. The purpose of this work is to develop practical recommendations for CFD calculations of centrifugal compressors based on the validation of a model of NASA High Efficiency Centrifugal Compressor experimental radial compressor stage. Results of a grid independence test are presented, and the optimal grid size for the High Efficiency Centrifugal Compressor stage is identified as comprising 3 million elements. CFD-calculations of an experimental stage were performed with different turbulence models. The obtained data was compared with the NASA experimental data considering integral (total pressure ratio, mass flow rate, adiabatic efficiency) and differential parameters (static pressure distribution downstream the vaned diffuser). The required CFD computational time for different turbulence models was calculated. Based on the results of this research, recommendations were formulated for the application of SST, k – ε, BSL EARSM and GEKO turbulence models for numerical modeling of centrifugal compressors.
99-111
Method of scanning thin surfaces in repairing gas turbine blades
Abstract
Improving the efficiency of weld overlay repair of gas turbine blades by developing and implementing a method of scanning complex curved surfaces of gas turbine blades directly on the machine is the aim of this work. The paper proposes an approach to scanning a blade with a computer vision system mounted near the nozzle on the same machine that is used for direct metal deposition. The computer vision system consists of a triangulation laser sensor and a camera. The proposed algorithm is adaptive to the mechanical condition of the equipment used for scanning and metal deposition. The scans obtained from the machine vision system have precision better than 0.05 mm in 67.56% of cases, and precision better than 0.1 mm in 95.75% of cases. That accuracy, with a laser spot of 0.5 to 1.0 mm, is sufficient for further use of the scans in repairing gas turbine blades. The proposed approach makes it possible to speed up the preparation of technological programs for direct metal deposition by 10 times compared to the manual scanning method.
112-124
Investigation of the edge effect in composites using the ANSYS software in a two-dimensional formulation
Abstract
The possibility of using the universal software ANSYS to study the concentration of interlaminar stresses near the free edges of laminated composites in a two-dimensional finite element formulation is considered. In this case, the cross-section of a rectangular four-layer composite plate of finite width with free side edges subject to uniform axial deformation is simulated. To create it, an original technique is proposed which consists in using thermal stress. The presented calculation results are in good agreement with the results of other authors.
125-134
Model of the turboprop engine reduction gear tooth harmonic spectral component
Abstract
The width of spectral components in rotary machines is determined by the frequency modulation of the carrier from the rotor speed deviation in the stationary operation mode. It was shown that, for the tooth spectral component, it is not enough to take into account this factor only. The analysis of publications and the studies performed show that it is also determined by the effect of many other factors: process-related ones (errors in manufacturing and assembly of gear wheels), operation mode parameters (rpm, temperature, transmitted load); design-related factors (flexibility of drive parts; modification of the tooth face), as well as uneven wear of tooth flanks. Using the planetary gearbox of a turboprop engine as an example, the structure of the tooth spectral component width in function of the analyzed influencing factors was considered. Based on the vibration statistics for eighteen gearboxes in overhauled engines, the choice of a ratio for the spectral component width of a frequency modulated process was justified. This choice showed readings closest to the corresponding experimental data. For the vibration of ten gearboxes with different degrees of tooth flank wear, the corresponding dependence of the width on the wear is presented. A mathematical model for the tooth spectral component width in overhauled and newly manufactured gearboxes as the product of the constant coefficient with the deviation dispersion sum from the considered factors was proposed. The same dependence was also given for gearboxes with wear when adding the dispersion from wear to the dispersion sum. It was demonstrated that, for the presented case of the maximum wear, its fraction in the total width was about 50%, whereas the fraction of the frequency modulation from the operating system of adjusting relative rotor speed constancy in the stationary engine operation mode was equal to half of all the other factors.
135-144
INFORMATION SCIENCE, COMPUTING TECHNOLOGY AND CONTROL
Complex of algorithms for fast determination of the parameters of motion of high-speed vessels in the digital signal processing system of a space synthetic aperture radar
Abstract
The article presents the main considerations for determining the tangential velocity of high-speed vessels in the digital signal processing system of a space synthetic aperture radar with an amplitude-phase program discriminator in the azimuth channel. The article suggests a complex of algorithms for fast determination of the parameters of motion of high-speed vessels in the digital signal processing system of a space synthetic aperture radar. The article contains the results of semi-natural experiments that confirm the reliability of the algorithms and their effectiveness in solving the problem of observing the sea surface.
145-157
JUBILEES OF SCIENTISTS
Power plants of the first aircraft
Abstract
The article is dedicated to the 140th anniversary of the construction of the first Russian aircraft designed by Alexander Fedorovich Mozhaisky. The main attention is paid to a comparative assessment of the parameters of the power plants of the Mozhaisky aircraft and some of the best known of the first heavier-than-air manned aircraft driven by a propeller. For the analysis, data published in various sources were used, primarily on the parameters of the elements of power plants (engines and propellers). An assessment was made of the sufficiency of the engine power of the first aircraft needed for their flight. The published materials of detailed studies of the aerodynamics of aircraft by A.F. Mozhaisky and the Wright brothers were used as the basis for an expert qualitative assessment of the aerodynamic characteristics of the compared aircraft. An analysis of the known statistical data and the results of the calculated estimates made it possible to show the impact of engine improvement on the progress in aviation.
158-169