Vol 59, No 3 (2016)

A method of determining the maximum permissible values for diagnostic signs, being an integral part of health and usage monitoring systems (HUMS) of the helicopter transmission units, has been developed based on a probabilistic approach.

This study proposes an approximate solution to a contact problem of dynamic deformation of a cyclically symmetrical discretely ring-stiffened cylindrical shell, the side surface of which is subjected to an evenly distributed inertia live load. The solution of the problem assumes the quasistatic mode of deformation of the structure. Several critical velocities of the live load have been found. A number of examples are presented.

We developed a triangular discretization element of the fuselage fragment in the form of a thin shell compatible with the adjacent elements based on Lagrange multipliers. Solution of several test problems showed a high efficiency of using the modification of a triangular finite element being proposed.

We resolve a problem how to control the longitudinal angular motion of flight vehicles (FV) having a system to displace the center of mass in the transverse direction. A structure is determined and a control law is established to start up and shutdown the engines. Formulas to determine the control parameters are obtained.

A method is proposed that allows searching for the required helicopter control of the flight on a given trajectory in a three dimensional space based on the mathematical (simulation) model. An implementation algorithm is provided. An example of computing the helicopter flight trajectory is given for a steady level turn regime.

Optimization of project-ballistic parameters of the spacecraft with propulsion systems with energy accumulation during the orbital transfer between low Earth orbits in the non-central gravitational field of the Earth is considered. The mass model of the spacecraft with an uncontrollable power-limited engine with the energy accumulator is used. The method of the project-ballistic optimization is obtained as an iterative procedure. Energy storage usage efficiency during the orbital transfer between low Earth orbits is estimated.

We consider the problem of calculating the ideal non-compressible fluid flow around the airfoil with jet blowing through a channel in the presence of a point vortex with a given circulation in the flow. The effect of the vortex coordinates on the aerodynamic characteristics of the airfoil is investigated and the optimal position of the vortex for maximal lift is found.

Results on the experimental investigation of a novel open-type mixing device with a twophase bubble structure working fluid for gas-droplet jet formation are presented. We study the effect of mode parameters upon velocity fields and droplet atomization obtained at the mixing device outlet.

Numerical modelling of fluid film break-up is carried out using adaptive mesh models. The results obtained are compared with experimental data. It is shown that using local adaptation with hanging nodes allows reaching a sufficient accuracy of fluid film boundaries estimation and definition of droplet dimensions resulted from its atomization. It is noticed that these are not only a turbulence model and adaptation sequence selection that substantially affect the computation results but also a type of initial mesh model.

We discuss the use of multilayered annular-plate dampers as rotor supports in turbopumps of the RD-0120 and RD-0146 rocket engines. We present a technique of calculating the elastic and damping characteristics of multilayer corrugated annular supports in the case of the conical precession of the rotor.

In this paper, we study the static and dynamic characteristics of imposing the valuecontrolled negative and positive electric charges on hydrocarbon fuel drops in the sharply inhomogeneous electric field of a fuel injector spray as applied to aircraft engines.

Proceeding from the first assumption of kinetic-molecular theory, the authors propose the Toms effect on reducing the hydrodynamic drag in a turbulent flow with polymer additives and its usage in power plants, to be explained.

The paper describes the design concepts, a brief theory, and analysis of the power and metrological characteristics of the fiber-optical digital-to-analog converters as the elements of multiplexing the data from onboard position sensors in aircraft instruments and systems.

Innovative methods of preform manufacturing using the TFP technology, radial braiding as well as the description of equipment are presented. Efficiency of Siemens NX, FiberSim and PAMRTM (ESI Group) software for design and simulation of integral panels and technology is demonstrated.

This paper presents the results of calculating the dibasic solid propellant underwater ignition by an incandescence spiral installed in a heat-resistant glass with the double bottom plates.