Том 60, № 2 (2017)
- Жылы: 2017
- Мақалалар: 25
- URL: https://journals.rcsi.science/1068-7998/issue/view/14240
Aircraft Equipment
Structural Mechanics and Strength of Flight Vehicles
Nonlinear deforming of laminated composite shells of revolution under finite deflections and normal’s rotation angles
Аннотация
The discretization of the boundary value problem for laminated composite shells is based on the finite difference approach using the regular mesh with the constant grid step and the difference operators of the second order of accuracy. The dynamic relaxation method is proposed for the solution of the nonlinear problem. The evolutionary equations of the dynamic relaxation are constructed, and the optimum parameters of the converging linear iterative process are estimated.
The influence of the noise field on parametric oscillations of flexible square plates
Аннотация
This paper examines the impact of the external field intensity of white noise on the nonlinear dynamics of square plates under the longitudinal load. It is shown that in some cases, the noise of high intensity is able to reduce the number of frequencies in the oscillation spectrum of the system.
Flight Dynamics and Control of Flight Vehicles
Comprehensive approach to mathematical modeling and helicopter flight task optimization
Аннотация
A comprehensive approach is proposed that allows modeling the flight of helicopter over the entire range of flight speeds. We also consider a technique for optimizing the trajectory corresponding to the flight task taking into account the terrain and operating conditions.
Precision tracking algorithms of civil aircraft by radar information
Аннотация
The problem of radar tracking of air traffic management by multiple model algorithms is discussed. Three types of multiple model algorithms are described. The various types of hypotheses combining algorithms are discussed. The simulation results are presented.
Aero- and Gas-Dynamics of Flight Vehicles and Their Engines
Coupled CFD/CSD simulation of the helicopter main rotor in high-speed forward flight
Аннотация
The helicopter main rotor in forward flight is considered in this paper. The results for rigid blades and elastic blades are compared by the method of coupled simulation. The influence of the structural damping coefficient on the blade in-flight deformation is also considered.
Aircraft and Rocket Engine Design and Development
Numerical determination of the gas-dynamic behavior of vane cascades with various deflection angles of the trailing edges of longitudinal ribs of an advanced gas-turbine engine thrust reverser
Аннотация
The work comprises numerical investigation of the influence of the deflection angles of the trailing edges of longitudinal ribs on the gas-dynamic behavior of vane cascades of a thrust reverser located in the secondary flow of a bypass turbofan engine (BTFE). Verification of the numerical model was performed on the basis of experimental research.
Influence of the helicopter flight design speed on the selection of working process parameters for GTE
Аннотация
This paper considers issues of designing a gas-turbine engine in the helicopter system at the early design stages. The optimum and rational values of engine working process parameters at different flight speeds of the flight vehicle (FV) are analyzed. Several characteristics of mathematical models (MM) that form the helicopter–engine system, are described.
Influence of combustion chamber geometry and compression ratio on the main parameters of a diesel aircraft engine
Аннотация
This paper considers the problem of increasing the fuel efficiency of a diesel aircraft engine and decreasing the smokiness of its exhaust gases (EG) by means of the experimental determination of optimum compression ratio and combustion chamber dimensions. Necessity for matching of these parameters in a wide variation range of load and crankshaft speed was identified and proved.
Trends in research of hydrodynamic damping in rotor supports of gas turbine engines
Аннотация
The paper studies different types of dampers for rotor supports of gas turbine engines (GTE). The advantages of hydrodynamic dampers are shown. Hydrodynamic dampers for GTE rotor supports are studied. A new design and technique of calculation are proposed for an adjustable hydrodynamic damper.
Layout of the power plant with an odd number of engines on the wing of the middle-range passenger aircraft
Аннотация
The layout of the power plant on the wing of a twin-fuselage passenger aircraft with an odd number of engines is compared with the single-fuselage aircraft-prototype. The advantages of the twin-fuselage layout being proposed are revealed.
Aircraft and Rocket Engine Theory
Thermal state of the shell for supersonic part of the ramjet nozzle
Аннотация
A mathematical model describing the temperature distribution in a non-cooled nozzle shell was constructed. Analysis of this model showed that the extreme temperatures are permissible for some modern and promising heat-resistant composite materials.
Analysis of hydrodynamic unsteady turbulent flow structure in an aircraft power plant channels
Аннотация
The authors performed an experimental study of the effects of non-isothermal and unsteady hydrodynamic conditions on generation and evolution of turbulence. Measurements of the instantaneous axial and radial velocities and temperature in unsteady conditions, calculation of their average and pulsation magnitude, and their correlation were carried out. A physical model of the hydrodynamic unsteady turbulent flow was formulated based on the analysis of the frequency spectra of pulse parameters.
Mathematical modeling of thermal modes of thermosyphons in operation with characteristic heat loads of aircraft equipment batteries
Аннотация
Numerical analysis of thermal conditions for a two-phase closed thermosyphon using the ANSYS FLUENT software package has been carried out. The characteristic temperature distribution, streamlines and velocity vectors for various heat loads have been obtained. The study has found the possibility of using the software package for analysis of the energy transfer processes at high thermal loads.
Dynamic behavior of the gas turbine engine regenerator with complanar channels
Аннотация
This paper expounds a technique for calculating unsteady gas temperatures, air and heat transfer elements of the corrugated plate of a recuperative heat exchanger with complanar channels for start and shut-off modes of the regenerative turbine engine. Under consideration are the distribution of thermal stresses in the plate, heat exchanger service life under stationary conditions, and the allowable number of dynamic “start–shut-off” cycles.
Aircraft Instruments and Instrumentation Computer Complexes
Predictive information design for the novel generation of display for the highly-augmented aircraft
Аннотация
We consider the task of predictive information design allowed for improvement of flying qualities in precise tracking tasks, in particular for the landing of an aircraft, the dynamics of which is characterized by the transportation time delay.
Analysis and synthesis of the information-controlling system channels to prevent critical operating conditions of the helicopter flight
Аннотация
This paper deals with the technical features of designing an information-controlling system to prevent critical operating conditions of the helicopter flight, a technique for evaluating its effectiveness, analysis and synthesis of the measurement channels, forming of warning signals, and information support of the crew in abnormal situations.
The effect of detuning of the partial frequency of MEMS gyros sensing elements on the amplitude-frequency response
Аннотация
The effect of detuning the partial frequencies of MEMS gyroscopes on its amplitudefrequency response is investigated. The formulated mathematical model allows defining requirements for the tolerances on gyros parameters, which determine the values of gyros partial frequencies, at the design stage of the sensor.
Aircraft Production Technology
Cyclic folding of composite zigzag structures and calculating of equipment parameters
Аннотация
A novel processing scheme for cyclic production of composite folded structures from continuous sheet of prepreg is presented. A circular transformable mandrel is used as a shaping unit. A technique of calculating the shaping unit parameters is developed. It is based on the analysis of facility kinematics using a vector model of four-axis folded structures transformation process.
Design of gating systems in production of gas turbine engine blades
Аннотация
The methodological background of designing the casting technological processes by controlling cast workpieces solidification process is considered for gas turbine engine blades. The general structure of software packages for computer-aided calculations of casting process parameters for the blade class cast product is presented. The example of designing the gating system for a specific product is given.
Radio Engeneering and Communication
Studying the positioning accuracy for dynamic (moving) objects with the use of multifrequency oblique-incidence sounding of ionospheric radio channels by chirp signals
Аннотация
The paper presents the methods and algorithms for positioning the dynamic (moving) objects using the oblique-incidence ionospheric sounding by chirp signals. Full-scale experiments have been performed to determine a distance to an object and its location.
Physical modeling of electromagnetic interferences in the unmanned aerial vehicle in the case of high-voltage transmission line impact
Аннотация
A technique has been developed for studying the interference resistance of electronic systems for unmanned aerial vehicles based on physical modeling The paper proposes mathematical models, a scheme of a test stand and examples of parameter calculation for physical modeling of electromagnetic interferences in communication links of the unmanned aerial vehicle in the case of electromagnetic fields of high-voltage transmission lines interference. Examples demonstrating successful implementation of physical modeling for similar tasks ascertain the feasibility of this approach.