AbstractThis paper analyzes the types of flight accident events, their causes and statistics on accidents at different stages of flight. By studying the subjective pilot rating, the law of its probability distribution was established as well as the possibility of using this law to assess the risk of accidents. The methodology for assessing the risk of an accident during manual control in nonstationary

AbstractA model for two-phase flow is proposed using a two-phase liquid-gas jet device as an example. The proposed model analyzes a separate flow of fluids and superposition of flows with account of their mutual influence. A comparison with test results is presented.

AbstractThe method of choosing the optimal number and distribution of work by stages is considered (based on providing the same total pressure recovery coefficient in stages and blade rows). A method is proposed for choosing the solidities of the profile cascades. The method effectiveness is confirmed by an example of choosing the optimal number of stages (three) and the distribution of work in a low-pressure

AbstractThe paper is devoted to estimation of parameters of technological inheritance based on the energy concept. The features of energy aspects and their technological inheritance are described by the help of processes occurring in parts during the manufacture, operation, and repair.

AbstractThe paper presents a technique of designing the mathematical dependences and standard reference tables for cases, when the independent variables and desired value are specified by some interval of permissible values.

AbstractTechniques of adaptive, situational, and reflexive control of information resources of telecommunication system were developed to ensure the information security while preserving the efficiency of information exchange under conditions of information technical impacts. The possibilities of reducing delays in message transmission have been assessed under the protection implementation during an

AbstractThe paper deals with the analysis of cycle features in the cooled turbine nozzle with asymmetric end surfaces. Influence of asymmetric end surfaces, which have been obtained in the course of turbine stage optimization, on the structure and dynamics of secondary flows in the blade passage is shown. Features of film cooling arrangement on the nozzle asymmetric end surface are analyzed. The method

AbstractThe paper elaborates on promoting the strength of self-organizing large-scale vortical structures in diffuser dimples aimed at heat transfer enhancement in cooled turbine blades. Conditions, under which the extended diffuser length is formed in the reverse flow inside the dimple, are revealed.

AbstractThe paper considers the transformable elements of the space nuclear power plant heat removal system located in the hinge joints of deployment system and ensuring transfer of the radiator from starting to working (orbital) position. Welded plate bellows and metal hoses are considered as transformable elements. The results are presented of computational and experimental studies performed on models

AbstractThis paper presents the simulation results for the three-layered aluminum honeycomb panels with face sheets made of composite aluminum alloy filled with silicon carbide particles. The effect of the filler volume fraction on the load bearing capacity of a simply supported panel under condition of static loading with uniformly distributed pressure and under the impact over the panel surface with

AbstractThe possibilities to use the M-corrugation type folded aggregates as a part of multilayer panels of the aircraft structures are investigated. A method avoiding complex kinematic calculations for modeling the M-corrugation type folded structure by means of modern computer-aided design systems has been developed and tested. The prospects of developing similar models of the folded structures based

AbstractThe results of studies are presented of fatigue-determined failure causes of the blower impeller of aircraft gas turbine engine core based on vibration mode patterns obtained by the holographic interferometry. Recommendations for detuning from the resonance are given that allows the part destruction to be eliminated.

AbstractA method based on the complex application of the actuator disk and finite-blade vortex theories is presented for aerodynamic design of the pusher propeller of a promising rotorcraft for vertical takeoff and landing. The software package was created that allows us to select the propeller parameters, create its 3D model and calculate aerodynamic characteristics in semi-automatic mode.

AbstractThe paper deals with the issues of the combined radio wave and thermal test methods for nondestructive testing of polymer composite materials (PCM) in laboratory and factory conditions.

AbstractThe paper presents the calculation results for ejectors with curvilinear and subsequent rectilinear sections of a mixing chamber. The reasons for choosing the curvature radius of a curvilinear section and the length of a rectilinear section in the mixing chamber are given. The effect of the flow separation in the mixing chamber on the ejector operation is analyzed.

AbstractThe paper describes the structural-functional scheme of quality control designed for main steps of the mass production technology process of products made of composite materials.

AbstractThe problem is analytically solved of synthesis of the longitudinal motion stabilization law of a single-rotor helicopter at the lack of information about the vertical speed of its motion. The solution is based on the method of output control synthesis of the MIMO-system motion spectrum to be used as a basis of an especially designed multilevel decomposition of the dynamic system model in the

AbstractThe up-to-date methods of computational fluid dynamics (CFD) were employed to study the effect of mass flux ratio above the submerged part of a solid rocket engine nozzle with a contoured inlet on the discharge coefficient. The results are given in correlation with the inlet geometry and nozzle submergence.

AbstractThe analysis of the initial level and kinetics of the mechanical characteristics depletion of the EI698-VD alloy was performed depending on the lifetime of the NK-family turbofan disks operating as a part of gas pumping units.

AbstractThe statement and the technique of solving a new class of problems for calculating the process parameters of the manufacture of inflatable bearing surfaces of aircraft are proposed. The technique development is based on dependencies of interaction dynamics of the stretchable fabric with internal pressure in the wing cavity. The model takes into account the imbalance of the pressure and tension

AbstractA takeoff-monitoring algorithm is proposed that allows predicting the rate of an aircraft takeoff run and recognizing emergency situations that require reject the takeoff. The algorithm is based on combined use of a polynomial approximation of the dependence of the takeoff speed on time and the CUSUM test to detect abrupt changes in the dynamics of the aircraft. Mathematical modeling of the

AbstractThe paper introduces the ways to improve the control accuracy of the parallel kinematic mechanisms of space application. The sources of errors in positioning and orientation of the mechanism developed are given. The ways are suggested for compensating the kinematic and temperature errors of linear drives and mechanism members.

AbstractThe features of identifying the damping properties of viscoelastic materials caused by their dependence on a large number of external factors are discussed. The main propositions of the international standard on the experimental method for determining the damping properties of viscoelastic materials under cyclic tension–compression are analyzed. A refined finite element model of the dynamic

AbstractThe problem of analytical approximation is solved for the functional dependences of navigation parameters of aircraft, the flight paths of which are the geodetic lines of an ellipsoid or spherical orthodromic lines. The obtained functional dependences make it possible to significantly reduce the instrumentation of the measurement and navigation system of the aircraft and the computational costs

AbstractThe study is intended to improve the quality of transients in sliding that is noninvariant to indefinite bounded disturbances. The action of disturbances is compensated by a special formation of a sliding manifold with the state coordinates reduced to zero values with a finite speed. The solutions of the listed problems are considered for the case of equality of the system dimension n to the

AbstractA method for constructing a solution to the problem of long-term durability and rigidity of gas turbine engine blades under thermomechanical load is considered. The solution is based on a three-component model of long-term deformation.

The optimization of the aerodynamic load distribution (circulation G) has been performed along the span of the complex lifting system, which provides the minimum induced drag. Optimization computations have been conducted for a set of aerodynamic configurations. Aerodynamic design has been performed by an example of a closed, optimized, biplane-type lifting system relating to the category of nonconventional

Hydrodynamic models of the low-viscosity fluid flow through the turbopump bearing and flowing fluid loads on the bearing parts are considered. Examples of calculations are given.

This paper presents the data gained through calculations of the eigenfrequencies and vibration modes of closed and semi-open impeller types by applying the finite element method and comparing holographic interferometry experimental data. The frequencies of exciting loads are considered and the expected resonance modes are shown.

The structural diagram of the multi-frequency correlation log-echo sounder and its operation fundamentals are considered for providing the safe landing and water area navigation of an amphibious unmanned aerial vehicle by means of processing both the amplitude and phase characteristics of the ultrasonic echoes with multiple f, 2f, 3f, … nf frequencies.

A new technology is suggested for cleaning duplex nozzles of the aircraft engine fuel manifold from products of carbonization and carbon deposits. This technology can be implemented without removing the engine from the aircraft and its disassembly. The experimental development of the technology is performed for different operation modes, the most effective conditions of cleaning are defined, endoscopic

The rendezvous of two spacecraft (passive and active) using a tether system is studied. Two laws of the tether control are proposed to ensure the safe rendezvous of bodies. A minimum allowable thrust of the active spacecraft and the parameters of the tether control laws are defined, under which the rendezvous is implemented safe. Based on the results of numerical simulation, the ability to control

The influence of a bilateral flare of the flow path of the turbine nozzle vane on the flow pattern and energy losses was investigated, a search was made for ways to improve the aerodynamic performance of a such kind of units. According to viscous flow calculations, the bilateral flared flow path affects the airfoil loading along the whole height of the vane, increasing velocities on both sides of the

The mechanism of flame stabilization in phase-inhomogeneous air—fuel mixtures is considered. A method is proposed for refining the thermal theory of flame stabilization by taking into account the heat consumed for heating and evaporation liquid fuel in the ignition zone. An analytical dependence is obtained for the calculation of flaming out curves during the steady combustion of two-phase mixtures

The technology is revealed for measuring air parameters aboard the single-rotor helicopter using the information of the aerodynamic field of a main rotor vortex column perceived by a fixed multifunctional receiver made as a two-channel scheme with an ion-mark and aerometric channels. The algorithms of forming and processing the information, technical characteristics of the system obtained by the results

Based on a new fracture mechanics parameter, this study is concerned with assessment of the lifetime of a cracked aircraft gas turbine engine compressor disk operating under low cyclic loading conditions. In combination with the elastic-plastic properties of the VT3-1 titanium alloy, various combinations of angular velocity, temperature, surface flaw form and size are considered. A lifetime prediction

The paper studies the effect of drag reduction in a two-medium boundary layer due to sliding at the interface region. The results obtained by authors in the framework of the boundary layer theory are in good agreement with those obtained by integrating the continuum equations of motion for film flows in the ANSYS Fluent package with reduction of computational time for the first case.

The problem of synthesizing the pitch angle control system with the angle of attack limiting channel is considered. The problem of matching the trajectories of the system of the pitch angle control mode and the angle of attack limitation mode is discussed. An approach is proposed based on using a generalized characteristic of the system, which ensures the matching the states at an arbitrary moment

On the basis of bench tests, the relationship between the vibration signal and the state of the gear coupling of the Mi-26 helicopter is shown. By the methods of spectral transformations and Hilbert–Huang transform, informative signs are established that characterize the wear of teeth and splines. The results obtained can be used in the on-board diagnostics system of the helicopter to determine the

A portable normal incidence interferometer is developed, which allows determining the acoustic characteristics of the full-scale liners of an aircraft engine. Studies of large sound-absorbing panels used for lining the aircraft engine ducts are carried out. It is demonstrated that the panels have uniform acoustic characteristics in azimuthal direction.

The paper deals with the problem of constructing the distribution law of the normal component of injection velocity in a turbulent boundary layer at supersonic flow velocities. The problem is solved using the Dorodnitsyn generalized method of integral relations and the Lagrange formalism. The computational experiments conducted have shown the efficiency of optimal controls in comparison with the uniform

The paper discusses the possibilities of using the navigation user equipment on the basis of determining the angular position of space rockets in flight taking into account the special features of the control process. The task statement is given on clarifying the angular position on the active trajectory leg and identifying the abnormal operation of the meters of inertial navigation systems on the

The paper describes the computational and experimental investigation in selecting the design parameters of control surfaces and characteristics of the lift engines of a VTOL unmanned aerial vehicle. The general structural scheme of equations to roll, pitch and yaw control and stabilization is analyzed. Results of numerical simulation of the point-to-point autonomous flight are given.

As a result of 3D calculation in the ANSYS CFX software, combinations of ribs and oval trenches are revealed of the maximal thermal performance, intensification of heat exchange, and minimal drag coefficients.

An integrated method for optimization of a welded portion of a high pressure compressor rotor as a single object is developed. The minimum mass criterion is used in the optimization method; limitations are imposed in accordance with strength and stiffness requirements. An example is given of optimization of a typical welded portion of a high pressure compressor rotor resulting in mass reduction and

The paper studies the aircraft astro-inertial navigation system, which consists of an astronomical navigation system installed on a gyro-stabilized platform of inertial navigation system. The errors of this system arising from various disturbing factors are investigated. Methods based on system correction channels formation and using adaptive estimation algorithm are proposed for reducing these errors

Heat exchange surfaces for enhancing the heat transfer in aircraft heat exchangers are proposed. They are made in the form of periodically applied oval-arc and oval-trench dimples. The results of the primary experimental thermal-hydraulic studies of paths of different configurations are presented.

The paper presents the main results of the experimental study of acoustic characteristics of the propfan engine with a high-loaded contra-rotating open rotor. The measurements are made during the engine operation under static conditions. The power, directivity, and spectral characteristics of the power plant acoustic field are obtained.

An approach to design of the rudder—drive system taking into account the aeroelastic characteristics of the rudder is proposed. Mathematical models are developed that are used to solve problems of the rudder design parameters selection and the rudder—drive system stability analysis. An example of design of the rudder—drive system of the air-to-air unmanned aerial vehicle is given.

A criterion equation is proposed for estimating the heat generation equivalent to the total power loss for rotation of tapered roller bearings operating under conditions of the middle support of gas turbine rotors.

The design and operating principle of a wheel motor for landing gear are presented. The purpose of the work is to add the braking function and increase the energy performance.

The paper presents the results of calculating the strength properties for the fan blades of a regional aircraft gas turbine engine under consideration of manufacturing deviations. The models of blades with different geometric deviations on the airfoil being analyzed, the design model of the fan assembly, the strength properties being estimated, and the design scheme for a set of blades are described

The interaction of a spiral wire clamp and a line conductor (cable, rope) is considered to estimate the bearing capacity of the wire clamp and to determine its structural and technological properties. The corresponding boundary and initial value problems are formulated to compute the structural properties of multilayer tension and connecting spiral clamps of various finite lengths. The paper presents

The paper considers the solution of the problem of determining the topology of the heated load-bearing structure and the size of the load-carrying elements that provide minimum compliance within a given mass using the criteria method of evolutionary optimization. The test cases are solved.

The paper discusses the effectiveness of currently used methods of surface damping of bending vibrations for thin-walled structures. The special features of surface damping of vibrations using a free and constraining layer damping are analyzed from a physical point of view and practical application. A combined damping coating is proposed, which allows integrating the positive qualities of both of the

The measurement data of three magnetometer sensors were analyzed in order to assess the significance of effect of the mission and supporting equipment operation on the adequacy of measurements of the Earth’s magnetic field by airborne means of the technological Foton-M no. 2 spacecraft. The research results demonstrate the significance of the problem of such effect and allow us to develop measures

We propose an easy-to-implement algorithm providing the safe (collision-free) separation of the Soyuz MS crew transfer vehicle from the ports of the Rassvet (MRM-1) and Poisk (MRM-2) mini-research modules of the International Space Station at an arbitrary station attitude at the time of separation and angular velocities exceeding the maximum permissible for the current undocking algorithm. A criterion

A technique of multiobjective robust controller synthesis for an electro-optical device line-of-sight stabilization system with saturating actuators is developed on the basis of polytopic linear parameter-varying system theory. From the computational point of view, the synthesis procedure is reduced to convex optimization under constraints expressed in the form of linear matrix inequalities. The multiobjective

The possibility of using penetrators to study the Moon’s subsurface is considered and possible launch options are indicated. Dependencies are given that allow calculating the penetrator mass, penetration depth, and arising overloads with sufficient accuracy. The use of a solid propellant engine on a penetrator is demonstrated.

Based on the experimental studies of models in a vertical wind tunnel, an aerodynamic solution was found in the form of an extension in front of the horizontal tail of certain geometry, allowing considerable improvement of spin characteristics and ensuring the spin recovery by various methods that is especially important for a trainer aircraft. The paper presents the results of experiments on dynamically