Vol 8, No 4 (2022)

The contemporary power plants use gas-turbine engines (GTE) as the main part. The gas-turbine engines DU80 and DN80 performing a power of 25 MW manufactured by “Zorya-Mashproekt” are used as gas-compressor units at the facilities of PJSC “Gazprom”. The above mentioned GTEs possess a specific design drawback and poor characteristics of the 3rd and 4th stages low-pressure compressor (LPC) blade row, this leads to early engine malfunction and increased repair costs. The PRIZ-1 measuring unit developed by Samara University is briefly described. This unit was used to research the vibration characteristics of the GTE DN80 3rd and 4th LPC blade stages on the test bench of PJSC “Tyumenskie Motorostroiteli”. This article shows the results of the performed non-contact measurements of the deformation state parameters of the GTE DN80 3rd and 4th LPC blade stages: the static blades position; the blades bending oscillations amplitudes; the gaps between the blade tips and the inner surface of the housing; the torsional blades oscillations amplitudes; the changes in the blades twist angle. The examples of the measured parameters visualizations are presented. The results of the LPC blades vibration characteristics research will be used in the process of design and technological works aimed at tweaking, increasing the reliability of the blade row and the overhaul life of the DN80 gas turbine engine.

The paper, using the example of an external gear pump, considers the solution of the problem of determining the node for separating the source of oscillations and the system of elements of the flow path is considered in order to simplify the study and analysis of hydrodynamic processes behind the source of oscillations. To separate the source of oscillations and the system of elements of the flow path, an experimental approach is used, during which the characteristic of pressure pulsations according to the “tooth” harmonic is determined behind the pump interacting with the serial RLC-circuit. An experimental study using dynamic analogies, methods of classical logic and methods of circuit theory made it possible to determine the connection node of the oscillations source and the system of elements of the flow path on the equivalent circuit, and in the graphic image of the flow part of the pump - to determine the corresponding section.