Vol 60, No 3 (2017)

A high-accuracy numerical scheme is proposed for vortex methods of flow simulation around airfoils of arbitrary shape including airfoils with sharp edges, because it does not require the solution continuity on the airfoil.

In this paper, a mathematical model of the nonequilibrium multiphase medium dynamics based on a two-speed two-temperature approximation of interpenetrative continuum mechanics is used to describe the nonstationary processes in a gas suspension. The influence of particle size and their volume content as well as the true density on the process of distributing a shockwave of pure gas into a gas suspension was investigated by means of numerical modeling.

This paper proposes to solve the problem of determining the strength properties of materials for thin-walled structural elements under mechanical and thermal loading as an optimization problem. A mathematical statement of the problem under certain assumptions is given.

The paper adduces the relators for algebraic operations on graphs using the numeric codes of the graphs. The special algebra of codes has been devised with consideration of the principles of graph transformation. This paper demonstrates the relevance of numeric coding of graphs for solving the problems of enumeration, systematization, and compact representation of the information about the structural and functional characteristics of the systems of flow distribution and conversion of rocket and space technology and for conducting the modeling transformations of given systems in the course of the structural and functional studies as well.

The paper describes a mathematical model of drop tests on the landing gear of the Ka-62 helicopter. The model is formulated using the multibody system simulation procedure based on the Lagrange equations of the first kind.

In this paper, we introduce a concept of coordinated turn that means the application of the lifting force being perpendicular to the UAV velocity vector and parallel to the surface on which the exact point target is located. Analytical solutions of the corresponding differential equations of the coordinated turn are derived.

The paper discusses a method of designing the neural controller for two-channel control of a technical object by an example of the roll and yaw control depending on deviations, velocities and accelerations of their variation.

This paper proposes a novel landing gear for spacecraft that allows a weight reduction due to using deformable crash legs. Numerical simulation of the landing process was performed.

As a result of the experimental-theoretical study of the loop (countercurrent) combustion chamber of the gas turbine engine, the data and theoretical dependences are obtained on the change in the combustion completeness and combustion temperature in various operating modes.

The paper presents a technique of calculating the life for gas turbine engine parts in a low cycle area based on the influence coefficients taking into account analytical and operational factors. A statistical method is used to determine the influence coefficients.

Features of fuel atomization and propagation in the flow behind a gas-dynamic stabilizer are considered. Estimations of the influence of transverse jets impulse magnitude on characteristics of mixing behind the stabilizer are obtained by numerical and experimental methods.

The analogy of molecular flows of gases, molecular heat transfer, and radiation heat transfer in transparent mediums is established.

The paper presents the results of studying the shielding efficiency for onboard cables of unmanned aerial vehicles (UAV). We specify the special features of studying the shielding efficiency for the onboard cables by means of a coaxial setup on frequencies more 3 MHz. The results presented in the paper experimentally verify that the shielding efficiency for onboard cables depends on the type of electromagnetic interference.

The paper contains a method of determining the aircraft motion parameters at landing based on the application of the ground optoelectronic system. The method proposed provides the certification of present-day instrument landing systems.

An optimal design of the starter-generator integrated into aircraft engines is studied. The authors give a review for modern designs and technical solutions of the problem.