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The article discusses the features of the inertial explosion of metal products and the prevention of its occurrence during its impact introduction of a metal penetrator into the ground of celestial bodies. The possibility of an inertial explosion in metal penetrators is determined when calculating the critical overload of the Gcr that exceeds a certain threshold value for each metal. These values are determined for a number of alloys and high-purity metals widely used in rocket and space technology for Earth and space temperatures. The features of reducing the critical overload threshold of the Gcr for space conditions at cryogenic temperatures and ways to prevent an inertial explosion are discussed

The task of increasing heat transfer of hydrocarbon fuel in the channels of cooling systems of liquid rocket engines is a matter of current interest. The article discusses the results of developing a mathematical model of an engine cooling system operating on super-circulation of fuel between the tank and the nozzle. The model makes it possible to determine the conditions under which the ratio of kerosene circulation in the nozzle cooling circuit would ensure that the selected material is used as the nozzle wall material, to find the minimum amount of kerosene in the tank required for cooling the nozzle by the proposed method.

To determine the performance characteristics of rubber-cord pipes under the influence of internal overpressure taking into account the relative displacement of the ends (flanges), an unconventional method of approximate analytical solution and the subsequent increase in the accuracy of calculating the stress-strain state of rubber-cord shells with tensile cord casing is used. The fundamental difference between the force created by the rubber cord pipe and the spacer force is taken into consideration. The calculation is compared with the results of experiments on fracture, the calculated value of the excess fracture pressure fits into the confidence interval of the spread of experimental data. Examples of constructing isobar power characteristics of sleeve-type pneumatic shock absorbers (sleeve tensilecompression shock absorbers) are shown and the features of their behavior are analyzed at different values of the operating and design parameters of the rubber cord pipe. The results are intended for engineering calculations and the optimal design of rubber cord pipes used to connect pipelines, or as air shock absorbers to protect technical objects from vibration and shock

The article discusses the results of an experimental study of cooling systems with intensification of inertial forces in a field, obtained on a modernized experimental bench. This stand made it possible to study the efficiency of heating the components of liquid fuel of a hydrocarbon coolant in the field of inertial forces and verify the results obtained in ANSYS.

A significant number of the main design parameters of the small upper stage for the group launch of small spacecraft with a propulsion system with a displacement fuel supply system determines the relevance of the random search method. The aim of the work is to create a method of selecting the main design parameters of the small upper stage by random search. The mathematical model based on the dimensional-mass model of the calculated mass determination provides the choice of the optimal mass of the upper stage, taking into account the complex relationships of the studied parameters

This article considers the development and research of a new design of crosshead-free piston hybrid power machine. After verification of a system of simplifying assumptions based on the fundamental laws of energy, mass, and motion conservation, as well as using the equation of state, mathematical models of the work processes of the compressor section, pump section, and liquid flow in a groove seal have been developed. In accordance with the patent for the invention, a prototype of a crosshead-free piston hybrid power machine (PHPM) was developed, it was equipped with the necessary measuring equipment and a stand for studying the prototype. Using the developed mathematical model, the physical picture of the ongoing work processes in the compressor and pump sections is considered, taking into account their interaction through a groove seal. Using the developed plan, a set of experimental studies was carried out with the main operational parameters of the crosshead-free PHPM: operating processes, temperature of the cylinder–piston group and integral parameters (supply coefficient of the compressor section, volumetric efficiency of the pump section, etc.). As a result of numerical and experimental studies, it was determined that this PHPM design has better cooling of the compressor section (decrease in temperature of the valve plate is from 10 to 15 K, decrease in temperature of intake air is from 6 to 8 K, as well as there is increase in compressor and pump section efficiency up to 5%).

A small closed volume occupied by the gas plasma is a specific feature of the propulsion systems for orbit correction of spacecraft (PSSC). We found the temperature of argon in the PSSC chamber using emission spectroscopy methods in the approximation of partial local thermal equilibrium.

The paper presents an active system for isolation of vibration, which compensates for the dynamic forces on the ground arising from the fluctuations of the elastically suspended mass with a vibro-active element by using the inertial forces in the antiphase. As the dynamic forces' compensator an electrodynamic drive is used, in which the linear movement of the rotor with an additional weight is carried out according to the information coming from a force sensor or accelerometer. The principle of the dynamic inertial compensation for the vibratory force boils down to the following: an oscillating mass actuator (compensator) with a mass on a movable body is mounted on the main body and with the reciprocating movement of the mass in an antiphase together with the motion of the elastically suspended vibro-active mass an additional inertial power is created, compensating for the vibro-active force at a given frequency. A possibility of mounting of an electrodynamic compensator is considered in this paper. The compensator is mounted on the oscillating weight, or on the body near the elements of the passive vibration isolation system. The active vibration isolation system with an electrodynamic compensator considered in this work can ensure an effective reduction of the power transmission to the base of the oscillation of the elastically suspended mass by 20-50 dB in the low frequency range.

Corrosion defects are the dominant cause leading to accidental destruction development on underground pipelines. Underground corrosion is one of the most complex corrosion types due to the fact that it is multifactorial and differs in the progressive participation dynamics of each parameter in the metal destruction process. It is necessary to introduce the biocorrosive activity criterion (CBA) as an additional parameter of corrosive factors. We conducted soil corrosiveness assessment adjacent to underground pipelines surface using physicochemical parameters complex and microbiological factors. Studies have shown the presence of soil samples near the pipeline with moderately corrosive bio-corrosive activity, potentially aggressive and slightly corrosive samples. A high level of soil samples detection with moderately aggressive bio-corrosive activity has been established. Sulfate-reducing and thionic bacteria were identified as bacteriological factors with a pronounced ability to cause a biocorrosion process on a metal surface, as well as a mycological micromycetic factor — fungi belonging to the genus Penicillium and Mucor. The conducted studies emphasize the need to apply the CBA evaluation as an additional parameter of the corrosion-significant factors complex in the appointment of repair work on the pipeline.

The paper proposes a systemic transition from the location and orientation of tolerance product features to linear and angular coordinates in the coordinate system of the product electronic model. The coordinate system is formed by designing datums set with a total informativeness content of six constrains on the object degrees of freedom, three of them being linear and three of them being angular constrains. The main design datums determine the object position in the product and form a generalized coordinate system. Auxiliary design datums determine the position of the attached object on the considered object and form an auxiliary coordinate system. Each element of the product has a certain informativeness content to limit the degrees of freedom, both linear and angular. When forming a Cartesian coordinate system, the datum element transfers piece or all of its informativeness content to it. As a result, the coordinate planes acquire different informativeness of three, two and one, and the coordinate axes acquire that of four, two and zero. The coordinate axes and planes informativeness content determines the number of linear and angular coordinates that can be set relative to them. Similarly, the feature datums informativeness means the number of linear and angular coordinates that must be specified in the coordinate system for its single-task location and orientation. The transition to a coordinate system for standardizing location and orientation deviations demonstrates compliance with a systematic approach that improves the quality of products in terms of the geometric specifications accuracy.

This study is devoted to the recent problem of quality assurance of technical products in the design process. However, it is impossible to solve this problem by using international standards ISO and geometrical product specifications developed by ISO technical Committee ISO/TC 213. They lack a reference system of geometrical characteristics, i.e. the coordinate systems of the products are not applied. On the other hand, the technical committee ISO/TC 184 – "Industrial automation systems and integration" introduced in their standards coordinate systems for the design of machine tools with numerical control, which made parts of products, 40 years ago, since neither design nor manufacture, nor the development of control programs or the control of parts after processing can be without coordinate systems. At the beginning of the XXI century, the same technical committee developed a series of international standards for the implementation of electronic geometrical 3D models of products, in the structure of which coordinate systems were introduced. Consequently, the coordinate system of products should be introduced in the standards for geometrical specifications ISO-GPS. With that study purpose, a new matrix of common GPS standards of a higher level on a coordinate basis was recommended.

The paper considers the types of heat transfer in the furnace chamber and ash residue values influence on the heat released and received in the furnace. The influence of different grades of coal (Kamyshanskij, Taldinskij and Ekibastuzkij deposits) with ash residue value from 16.4 to 43 % on the furnace combustion heat was analyzed. The ash residue value influence on the value of the heat received in the combustion chamber, which is the boiler efficiency defining characteristic, is considered. The graphical dependence of the heat amount received in the combustion chamber on the ash residue for the different types of solid fuel is shown.

The method for the experimental study of the viscoelastic properties of pneumatic elements with a rubber-cord casing is proposed. Based tests of relaxation in which the height of the pneumatic element is kept constant (a practically incompressible fluid is used as the working medium). The implementation of the method is illustrated by the example of the rubber-cord casing of the balloon type of model N-50. The value of the absorption coefficient (relative hysteresis) is established, which in order of magnitude coincides with the value of the absorption coefficient of tread rubbers given in literary sources. In the process of holding the height of the pneumatic element at a constant level, increments of the force of the pneumatic element and overpressure are proportional to each other with a proportionality coefficient depending on the value of the internal volume and height of the air element. The comparative analysis of the features of the operation of pneumatic elements in cases where the working medium is a gas or liquid is done. The results obtained are of interest in the development of vibration protection and vibration isolation systems for technical objects, the design of which includes air springs, air damping shock absorbers and rubber-hydraulic vibration mounts.

A method for the experimental construction of isobaric static (equilibrium) power characteristics of pneumatic elements with a rubber-cord casing at a constant temperature is proposed. This method also allows you to determine isobar geometric characteristics, establishing a relationship between the height of the pneumatic element and the increment of its internal volume relative to some fixed position. The practical implementation of the method is illustrated by the example of a pneumatic element with a rubber-cord casing of the balloon type of the model N-50. The agreement of the experiment with the theoretical data calculated by the traditional method, widely used in the scientific literature, is analyzed. The obtained parameters are mandatory for the model of air spring and study the damping phenomenon. The results of the study are intended to develop vibration protection and vibration isolation systems for technical objects, the design of which includes air springs and air damping shock absorbers.

The international organization for Standardization has developed a series of standards for the implementation of electronic geometrical models of products, where coordinate systems have been introduced for the first time. However, it is not considered in the electron models that the different functional purposes of both the coordinate planes and axis are differed. In order to improve the quality of project documentation developed with the help of electronic models, the geometric specifications of coordinate systems were determined, coordinate planes and axes were established to perform six basic 2D projections of the product. A new geometrical specification "informativeness" is introduced as the number of product degrees of freedom restricted by the base, coordinate plane or axis. The coordinate system of the product is materializes by a set of its design datums with a total informativeness of 6. Coordinate planes of the rectangular coordinate systems have the informativeness of 3,2 and 1, the coordinate axes -4,2 and θ (zero).

The paper presents the results of experimental studies of an arcjet thruster in pulsed mode of operation on nitrogen with a thrust value of up to 32 mN and energy consumption of up to 30 watts. The pulse mode of operation of the arcjet thruster is provided by the developed power source. At measured values of temperature at the nozzle and pressure in the arc chamber of the engine in a pulsed mode of operation define the basic characteristics of gas-dynamic functions of gas flow. The forecast of the achieved values of the specific impulse when using ammonia as a working fluid is carried out

During soil biocorrosive activity evaluation on the oil pipeline routes from the Khanty-Mansiysk Autonomous Region (Yugra) soil micromyceta detection actuality was evaluated. Also we studied the microbiological and physical-chemical indexes complex. Our studies allowed to distinguish weakly aggressive, moderately aggressive and potentially aggressive biocorrosive activity. Necessity of sulfur-cycle bacteria and soil micromyceta quantitative evaluation was shown for metallic structures biocorrosive protection development and dynamic control.

The aim of this work is to improve the quality of oil and gas valves with a rigid wedge in terms of integrity. The method of research presupposes modeling the geometrical specifications of the locking wedge in the coordinate system formed by the set of the major design datums of the wedge. This work result is tightness assurance of valves based on the separation of functions of the datums of the two wedge sealing surfaces into the sealing with informativeness three and the executive one with informativeness two. The datum with informativeness two is profiled in the form of two diametrically opposed areas on the wedge sealing surfaces and is used to make a sealing effort on the datum with informativeness three.

Technology of a local compaction of soil half-spaces, including tank foundations for liquid hydrocarbons storage has a high innovative potential. The use of proposed technology can help to reduce time and material costs to prepare a soil foundation providing its stability in the process of entire lifecycle of a designed facility. Laboratory researches of rammer’s operating element dynamics in a soil foundation were carried out to specify technical and technological parameters and to confirm theoretical data obtained previously by means of a specialized measuring system. The developed technique of performing laboratory researches allowed us to obtain data concerning the influence of free fall height of the rammer’s operating element model on the depth and its penetration velocity into a sandy soil. Laboratory researches showed that in the studied range of free fall heights, the model’s penetration depth value practically linearly depends on the model’s free fall height and grows with the increase of impact velocity of a model in a soil. The increase in the model’s free fall height in its turn leads to an impact time decrease on a soil. The obtained data showed satisfactory convergence of results in theoretical and laboratory researches of model’s velocity in a soil. Discrepancy of theoretical and laboratory results did not exceed 10 %.

Energy and resource saving is one of the most important economic target. The natural resources sustainable use makes possible not only to reduce the energy resources shortage economic problems, but also to reduce the harmful impact on the environment. A significant effect in solving this problem is achieved by the hydrocarbons transportation operating mode reasonable planning. The reasonable planning is based on the following: the energy resources use optimization, pumping equipment efficiency improvement, energy load shifting to less busy periods and to the cheap energy regions, reducing the load imbalance on the equipment and reducing the accidents and failures risk. The basic concepts, principles and operating mode optimization criteria were considered, the hydrocarbons transportation planning complex criteria application need was shown.

Flocculation methods for the oil refinery wastewater treatment are necessary, effective and economic, and are used, as a rule, for the demulsification of petroleum products from wastewater. In addition, flocculants can be used to remove other pollutants, not only oil products. The research purpose was to analyze the separate indicators level, measured on the oil refinery wastewater treatment facilities. Oil refinery wastewater purification rate was studied, indicating a different level of indicators considered. An influence of cationic and anionic flocculants working efficiency showed that the flocculants allows to increase the flotation technological indicators and to increase the solids content in water.