Study on the biparametrical transudations circuits with distributed parameters

This paper highlights the methods of resenting mode in the transudation with distributed parameters. The transient parameters of the power supply were analyzed. It was discovered that resonance is provided in a small range of movement of the moving component of the sensor in known turbofan engines, indicating that the known techniques of sustaining the resonance mode are flawed. Further study should focus on developing novel methods for preserving resonance mode over the entire range of change of the converted value, general principles of turbojet engine construction, and a complete examination of their resonant circuits, according to the findings.

Fabrication and Testing of Rocket Engine Construction Elements by Addictive Production Approach

For the first time, using the technology of selective laser sintering, prototypes of rocket engine compressor blades were manufactured with subsequent analysis of the strength, technological, physical and mechanical characteristics of the product. The physical and mechanical properties of the manufactured blades were investigated, it was found that the short-term strength limit at 20 °C is 1450 MPa, and at 300 °C the ultimate strength is 1300 MPa, thus thermal losses in deformation resistance are no more than 12%, which allows the material to be used in aircraft construction, including for supersonic aircraft

Influence of Various Heat Treatments on Hardness and Impact Strength of Uddeholm Balder: Cr-Mo-V-Ni Novel Steel Used for Engine Construction

The construction of an engine requires optimized geometry and superb material properties in various environments. Tensile and yield strength are not the only parameters essential to consider. Hardness, impact toughness, and ductile-brittle transition temperature (DBTT) are also crucial. In this paper, Balder, Chromium-Molybdenum-Vanadium-Nickel steel with low impact toughness attested is considered. It contains both high Nickel and high Vanadium content, a rare combination among iron-based alloys. This study aims at proving that conventional heat treatment can improve its impact toughness while maintaining hardness level, exceeding its to-date performance. Steel’s exact elemental composition was checked, and material samples’ hardness and impact toughness were measured. Four heat treatments were proposed, then hardness and impact toughness were measured again. It was established that impact toughness over three times higher than marketed (57.3 J against 17 J) can be achieved with simultaneous 2 HRC points (from 46.4 HRC to 48.4 HRC) rise in hardness. Achieved parameters place examined alloy at the high-ranking position among similar steels. Occurrence of temper embrittlement was avoided. Notably, the ductile-brittle transition was not observed in any sample.

THE RESEARCH OF POSSIBILITY OF GALVANIC CORROSION IN BRAZED CONNECTIONS USED IN AVIATION ENGINE CONSTRUCTION

The article presents the results of researche of galvanic corrosion possibility of brazed connections of steels 13Сr11Ni2W2MoV and 12Cr18Ni10Тi with use of the solders VPr4 and VPr50, which are used in design of aviation engineering engines. The research was carried out by electrochemical methods. Corrosion currents’ density and contact pairs’ potentials in chloride solutions have been determined. It is determined that 13Сr11Ni2W2MoV steel can be exposed to galvanic corrosion in a place of brazed connection. Thus the greatest danger to it is represented by VPr4 solder. The mechanism of corrosion of 13Сr11Ni2W2MoV steel in neutral environments has been examined and recommendations about its protection against galvanic corrosion are made.

ПЕРСПЕКТИВНІ НАПРЯМКИ НАУКОВИХ ДОСЛІДЖЕНЬ НА КАФЕДРІ ДВИГУНОБУДУВАННЯ

A retrospective of directions of scientific researches of employees of the chair of engine-building of physical-technical faculty is presented. The historical formation and development, achievements of the faculty's scientists in the field of rocket engine construction, as well as prospects or their further research are considered.