Vol 60, No 4 (2017)

The paper considers the issues of justification and choice of the stiffness and damping values for the active radial magnetic bearing depending on the preset “negative” stiffness of the suspension and the dynamic behavior of the rotor. We present an algorithm for continuous adjustment of the basic parameters of the PID regulator in the operating range of rotor speeds that provides the adaptive control of stiffness and damping for radial magnetic.

A functional diagram and algorithms of processing the measuring channels of aircraft air data system with a fixed non-protruding flow receiver are considered. The technique and analysis of methodical and instrument errors in measuring the altitude-speed parameters of aircraft in the system channels are presented.

The advantages of the bicalibre configuration of the volumetric packaging in comparison with the single-calibre one are shown within the framework of the concept of ballistic efficiency (BE) enhancement of the aerial vehicles (AV) with prevailing coast phase. The rational range of booster and coaster calibre ratios of bicalibre aerial vehicles for both solid propellant jet engines and combined propulsion units are defined.

A mathematical model and numerical scheme of the method being used are described. The results of calculating the helicopter main rotor aerodynamic performance in hover mode above a helideck are compared to the known wind tunnel test data.

The finite element algorithm developed by the authors has been used for solving the strength and stability problems of shells. The effect of deformation nonlinearity, stiffness of stringer set, shell thickness on critical loads has been determined.

This paper considers the problem of improving the flight safety in manual control of the aircraft. In order to prevent stalling, an algorithm of forming the pitch guidance commands is proposed. The effectiveness of this approach is confirmed by simulation of a closed-loop system “aircraft–pilot”.

In this paper, detection of objects in airborne systems of unmanned aerial vehicles using information about changes in the image of the terrain is considered. A proposed technique includes initial detection of objects by the level of local contrast over the field of the image misalignment function, calculation of the amplitude characteristics of objects, and their further filtering by a set of calculated values of characteristics.

We consider the variational problem of Newtonian friction minimization that affects surfaces in supersonic flows at the constant velocity on the outer edge of the boundary layer.

We studied the geometric models of combustion chambers depending on their simplification. It is shown that the error in calculating the parameters does not exceed 8 % under the constraint of the geometrical model of the gas turbine engine (GTE) combustion chamber by an angular sector with a burner device.

In this paper an attempt is made to conduct a direct numerical study of intra-chamber processes in a solid propellant rocket engine. An adjoin problem is formulated. To solve this problem, a set of computer applications was developed using the standard of multithreaded processing OpenCL. The results of calculations are presented.

In the paper, processes of high-energy electron beam interaction with plasma particles in a discharge channel of a stationary plasma thruster are analyzed and the results are presented.

The reasons for shortening the service life of blades and the rotor disk of a small-sized centripetal turbine are analyzed both at the maximum operating modes of the turbine and the starting and stopping stages. The ways of partitioning the rotor blade into elements and relating them to the disk elements in creating the mathematical model of strength analysis are considered.

This paper considers the aspects of consistency for dynamic analysis of rolling bearings and finite element stress-strain state analysis of its cages. The examples of calculations performed are presented.

This paper covers an advanced technique of finite element analysis of co-curing shaping process at high temperature of hybrid metal-composite structures. The technique allows us to model a technological production process and to evaluate the influence of design parameters of tooling on the deflected mode and strength of elements taking into account the contact interaction.

The paper presents the results of development work for creating a new generation compact airborne radar system. It sets out the basic principles of building the equipment, the tasks being solved, the techniques of upgrading and adaptation of compact radar systems to different types of aircraft and recommendations for their application.

The paper presents tools and techniques for studying the properties of porous heatshielding materials under conditions of abrupt change in pressure. We determine the gas outflow pattern from the sample volume and the pressure differential at which the sample is detached from the spacecraft element design.