Universal educational and research stand was developed for analyzing an electrical drive’s behavior with different load disturbance effects. Major components of the stand are two electrical drives with rigidly coupled shafts. As a result, first electrical drive (loader) has a capability to imitate effects of different loading types to another one (trial drive).

Control software for the stand is developed. It allows us to combine a variety of loading types and change parameters of current loading such as joint moment, damping, additional inertia, and external torque. Also there is a capability to imitate effects of elasticity and backlash of mechanical transmissions. The paper considers the main challenge of creating the given system, i.e. discretization with a variable step. Some methods to decrease its negative effects on system stability are suggested.

The given system allows to change loading parameters more rapidly and in a wider range as compared to a system with real mechanical outfit.

These stands are currently used for laboratory classes within the course “Electrical robotic drives” at SM7 department in Bauman Moscow State Technical University. Also the system of interdepended stands for semi-realistic simulation of manipulation systems is under development.

An improving dynamic quality of vehicles and enhanced fuel efficiency are gained thanks to the combined power system (CPS), comprising a main energy source - internal combustion engine (ICE) with an attained level of the power source - and an auxiliary energy source, i.e. an energy storage device (a flywheel).

To solve this problem was developed a mathematical model of CPS comprising internal combustion engine and flywheel energy storage (FES) with stepless drive.

The stepless drive of the flywheel is made to be hydrostatic mechanical to raise the system efficiency. To reduce the drive weight and simplify the control system in the hydraulic part of the flywheel drive is used only one hydraulic unit being controlled.

The paper presents a kinematic diagram of the track-type vehicle equipped with the CPS that has a hydrostatic mechanical drive of the flywheel and a mechanical transmission.

A mathematical model of the system comprising an ICE, hydrostatic mechanical drive, and FES with stepless drive has been developed. This mathematical model was used to study the influence of ICE and flywheel drive parameters on the dynamic characteristics of the system.

The paper estimates the impact of flywheel energy consumption, pressure in the hydraulic system, and control parameter of hydrostatic mechanical drive on the charging time of FES.

The obtained piecewise linear law to control the regulation parameter of the hydraulic unit allows us to minimize the charging time of the flywheel at the short-term stops and in the parking area of a tracked vehicle equipped with a CPS.

The causes affecting the performance of ‘ICE – drive – flywheel’ system in the course of the flywheel acceleration are a restricted maximum power of the engine, as well as a limited generating capacity, and a maximum flywheel drive hydro-system pressure.

The obtained results allow us to determine rational parameters of the flywheel and the laws of drive control to provide their further optimization, with a tracked vehicle being in motion, under random external effect.

The paper subject is a choice of the fluid composition for the heat exchangers (HE) of a closed-cycle gas turbine plant (CGTP).

The study of the fluid composition impact on heater dimensions is a subtask in designing a 25 kW long-resourced CGTP with gas temperature of 1273 K before the turbine for a remote autonomous consumer of energy. The aim of this study is to find the optimal mixture to have the HE minimum volumes of the CGTP. Herein, heating is provided through the heat supply from the combustion of various cheap kinds of fuel, which, in turn, may result in contaminating heat exchange surfaces. In the analysis an additional condition is that it is necessary to reduce the level of contamination of heat exchange surfaces, which is reached by using a HE tubular matrix and a turbulent regime of flow.

A mixture of inert gas and helium- xenon is used, as a fluid, to increase the life of the plant. The paper illustrates how the thermal conductivity and viscosity of the helium-xenon mixture depend on the percentage composition of helium in the mixture.

The paper describes in detail the effect of the helium-xenon mixture composition on the mixture flow parameters in the preheater and on the volume of its matrix. In addition, it gives the calculation results on how the helium-xenon mixture composition effects on the volumes of the regenerator and cooler matrices.

After assessing the impact of the helium-xenon mixture composition on the HE parameters their comparison is conducted in terms of volume and cost of materials from which to make them. From these data a conclusion is drawn that the heater volume has a great effect on the cost of heat exchange equipment, and it is advisable to choose the mixture composition with which its volume is minimal.

In modern supersonic aircrafts due to aerodynamic skin heating a temperature of hydraulics environment significantly exceeds that of permissible for fluids used. The same problem exists for subsonic passenger aircrafts, especially for Airbuses, which have hydraulics of high power where convective heat transfer with the environment is insufficient and there is no required temperature control of fluid. The most significant in terms of heat flow is the flow caused by the loss of power to the pump and when designing the hydraulic system (HS) it is necessary to pay very serious attention to it. To use a constant capacity pump is absolutely unacceptable, since HS efficiency in this case is extremely low, and the most appropriate are variable-capacity pumps, cut-off pumps, dual-mode pumps. The HS fluid cooling system should provide high reliability, lightweight, simple design, and a specified heat transfer in all flight modes.

A system cooling the fluid by the fuel of feeding lines of the aircraft engines is the most effective, and it is widely used in supersonic aircrafts, where power of cooling system is essential. Subsonic aircrafts widely use convective heat exchangers. In thermal design of the aircraft hydraulics, the focus is generally given to the maximum and minimum temperatures of the HS fluid, the choice of the type of heat exchanger (convective or flow-through), the place of its installation. In calculating the operating temperature of a hydraulic system and its cooling systems it is necessary to determine an increase of the working fluid temperature when throttling it. There are three possible formulas to calculate the fluid temperature in throttling, with the error of a calculated temperature drop from 30% to 4%.

The article considers the HS stationary and noon-stationary operating conditions and their calculation, defines temperatures of fluid and methods to control its specified temperature. It also discusses various heat exchanger schemes, makes recommendations for regulation of heat flows, power reduction of cooling system, and choice of heat insulation elements of HS.

About 95% of the electricity consumed by air compressor stations around the world, is transformed into thermal energy, which is making its considerable contribution to global warming. The present article dwells on the re-use (recovery) of energy expended for air compression.

The article presents the energy analysis of the process of compressing air from the point of view of compressor drive energy conversion into heat energy. The temperature level of excess heat energy has been estimated in terms of a potential to find the ways of recovery of generated heat. It is shown that the temperature level formed by thermal energy depends on the degree of air compression and the number of stages of the compressor.

Analysis of technical characteristics of modern equipment from leading manufacturers, as well as projects of the latest air compressor stations have shown that there are two directions for the recovery of heat energy arising from the air compression:

 Resolving technological problems of compressor units.

 The use of the excess heat generation to meet the technology objectives of the enterprise. This article examines the schematic diagrams of compressor units to implement the idea of heat recovery compression to solve technological problems:

 Heating of the air in the suction line during operation of the compressor station in winter conditions.

 Using compression heat to regenerate the adsorbent in the dryer of compressed air.

The article gives an equity assessment of considered solutions in the total amount of heat energy of compressor station. Presented in the present work, the analysis aims to outline the main vectors of technological solutions that reduce negative impacts of heat generation of compressor stations on the environment and creating the potential for reuse of energy, i.e. its recovery.