Журнал “НТС” №1 2022 (42)

PERFECTION OF REGULAR TECHNICAL DOCUMENTATION FOR PROVISION OF STRENGTH RELIABILITY OF AVIATION GAS TURBINE ENGINES

Yu. A. Nozhnitsky

Abstract. The main directions of perfection of regular technical documentation for provision strength reliability of aviation gas turbine engines are discussed. It is shown that perfection of regulatory technical documentation is connected with new requirements for aviation engines, application of new design and technological solutions, necessity of generalization of aviation engines development and utilization. Offers are formulated for correction of airworthiness requirements and methods for confirmation that aviation engine meet requirements are formulated. In particular it is shown that it is necessary to clarify conditions for consideration of aviation engine shutdown as a minor failure. It is offered to present methods of engine conformity assessment in the form of approved by aviation authority advisory circular of in the form of standard (or methodical recommendations) of state scientific centers, on the base of which certification centers are accredited. Examples of the most topical directions for perfection of regulations are given including application of composite materials and additive technologies; confirmation of main engine parts life’s taking into account possible defects; confirmation integrity of turbocompressor rotors takings into account possible shafts failure, disconnection or displacement; prevention of dangerous failures as a result of fan blade fracture, etc.

Keywords: Aviation Gas Turbine Engine, Regular Technical Documentation, Strength Reliability.

DETERMINATION OF DEFORMATION RESISTANCE CURVES OF TITANIUM ALLOY VT23 IN THE STATE OF SUPERPLASTICITY

A. V. Mendokhov, I. S. Petuhov, A. I. Evdokimov, S. V. Morozov

Abstract. Improving the technology of manufacturing parts of complex shapes remains relevant. New engine concepts are currently being developed. The authors developed an engine design with a composite cycle gas turbine engine and piston engines, with optimization of the working process parameters and ensuring required strength and dynamic characteristics.

Keywords: gas turbine engine, piston engine, composite cycle superplasticity, welding, temperature difference, linear deformations, tensile specimens, VT23 titanium alloy.

TECHNOLOGICAL SUPPORT OF QUALITY INDICATORS OF FLOW CHANNELS SURFACES

A. Yu. Grymzin, G. A. Sukhochev, O. N. Kirillov

Abstract. A technological scheme of the method and installation for finishing combined processing of parts with small-sized flow channels is proposed. Calculations of modes, tests and measurements of the obtained results are carried out, the possibilities of the proposed technology and further modernization of technological equipment are shown.

Keywords: flow channel, combined action, sleeve, electrochemical-mechanical finishing, consumption characteristics.

EXPERIMENTAL STUDY OF THE AEROSOL FILTRATION PROCESS USING PERFORATED FILTER BAFFLES

D. S. Protsko, S. Yu. Panov, A. A. Khvostov, A. A. Zhuravlev, O. A. Semenichin

Abstract. The results of an experimental study of the hydraulic resistance and the efficiency of capturing aerosol solid particles using perforated gratings, depending on the filtration rate, the initial concentration of particles, are presented.

Keywords: perforated grating, filtration, aerosols, trapping efficiency.

SOME FEATURES OF SOLVING OPTIMAL DESIGN AND CONTROL PROBLEMS FOR MULTISTAGE AXIAL COMPRESSORS

I. N. Egorov, G. V. Cretinin, K. S. Fedechkin

Abstract. Designing modern compressors with adjustable flow path elements requires finding both geometric parameters and optimal control laws for controllable elements. Some features of solving such problems with IOSO NM numerical multiobjective optimization method are considered in this paper. Using the rational strategy of multicriteria research allows improving the compressor efficiency to its possible limit. To achieve this goal it is required to choose the most preferred design from resulting Pareto front and apply sets of control laws, which is optimal for various compressor modes.

Keywords: axial compressor, parametric optimization, control law, mathematical modelling.

A COMPLEX METHOD FOR ASSESSING THE EFFICIENCY OF THE THERMOMECHANICAL COMPRESSOR

D. A. Uglanov, E. V. Blagin, O. V. Tremkina

Abstract. A thermomechanical compressor belongs to the category of devices that implement the principle of thermal compression — pressure increase due to heat supply. Currently, there are no recognized methods for evaluating the effectiveness of this class of devices. In this paper, three methods for estimating the energy efficiency of a thermocompressor are proposed. The first method is to determine the supply coefficient — the ratio of the mass of gas injected to the consumer to the mass of the filling. The second method is to evaluate the efficiency of a thermocompressor as part of the simplest heat engines. The third method defines the degree of perfection of a thermocompressor as the ratio of its performance to the maximum possible.

Keywords: thermocompressor, energy efficiency, feed rate, relative efficiency.

FEATURES OF TURBOPUMPS MANUFACTURING AND ASSEMBLING TECHNOLOGY INFLUENCE TO THE NON-CONTACT SEALS’ GAPS

A. V. Ivanov

Abstract. Each element of the turbopump unit has its own dimensions, tolerances of the shape and arrangement of the surfaces, which differ from the nominal ones. During assembling of the turbopump unit due to mounting displacements of sealing surfaces of the rotor and stator, they are located with some skew. In the article the factors influencing the mounting displacements of the seal rotor and stator elements are considered, the dependences for their calculation are given.

Keywords: gap, seal, skew, misalignment, manufacturing, assembly.

CALCULATION AND ANALYTICAL STUDY OF THE MAIN OIL PUMP CASING INFLUENCE ON VIBRATION ACTIVITY

S. V. Yaroslavtsev, D. N. Galdin

Abstract. The work is devoted to the study of changes in the level of vibrational activity of main oil pumps, which takes place for a certain design. Design optimization has been implemented.

Keywords: main oil pumps, vibration activity, frequency range, classification of hydrodynamic causes of vibrations in the oscillation spectrum, sliding bearing gauge, housing stiffening ribs, technical cybernetics, optimization.

BASIC OPERATIONS OF THE TECHNOLOGICAL PROCESS OF BRUSH SEALS MANUFACTURING. THEIR INFLUENCE ON GAS-DYNAMIC CHARACTERISTICS

Ya. A. Artamonov, A. I. Evdokimov, E. V. Rodin, S. P. Pavlinich

Abstract. An analysis of the influence of the geometric characteristics of the brush and its gas-dynamic properties was carried out. The most important seals for the most important technological operations for the manufacture of brush seals are considered, the influence of each of the technological operations on the subsequent one, the synergistic effect on the gas-dynamic characteristics of the assembly, is assessed. Influence on brush seal geometry.

Keywords: brush seal, manufacturing technology, geometric characteristics, gas-dynamic characteristics, GTD.

MAIN LINE PUMP IMPELLER WORK SURFACE RECONDITIONING

S. D. Novopoltse, М. N. Krasnova

Abstract. This article discusses the appearance origins of the concealed cavitational erosion in centrifugal pumps, the methods of pump impeller reconditioning in order to increase its performance characteristics.

Keywords: cavitation, reconditioning, laser metal deposition, main line pump, impeller, petroleum refinery.

TECHNOLOGICAL SCHEME OF PULSE-SHOCK HARDENING OF NARROWING CLOSED INTERSCAPULAR CHANNELS

A. M. Nekrylov, S. N. Kodentsev, A. O. Rodionov

Abstract. The technique of technological support of the specified parameters of the surface of a narrow narrowing channel with a twist along the radius and the regulations for the design of combined pulse-force hardening operations are proposed. A new patentable technological method has been developed for strengthening narrow narrowing curved channels by combined pulse-shock action with the advancement of an unfixed tool with low-frequency vibrations of the technological system.

Keywords: pulse-shock hardening, combined impact, low-frequency oscillations, hardening modes, interscapular channel.

RESEARCH AND DEVELOPMENT OF LASER WELDING PROCESS WITH CONTROLLED HEAT INPUT

A. B. Bulkov, V. F. Selivanov, V. V. Shurupov

Abstract. The results of studies of laser welding of titanium thin-walled structures with a limited heating temperature of the inner surface are presented. The design of the welded joint is proposed, which allows achieving the required thermal regime and ensuring sufficient mechanical strength of the product. On the basis of physical and mathematical modeling, the parameters of the welding mode are determined. Studies on the assessment of the quality of welded joints show that the developed technology ensures the production of defect-free welds with specified mechanical properties.

Keywords: thin-walled structures, laser welding, modeling, titanium alloys.