Browsing by Author "Sukhyi, Kostiantyn M."

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Assessment of the Efficiency of Hot Helium Tank Pressurization Systems for Oxygen-Propelled Rocket Engines
(Publishing House “Akademperiodyka”, Kyiv, 2025) Sukhyi, Kostiantyn M.; Voit, S. M.; Mitikov, Yurii O.; Spirkin, S. V.; Sukha, Iryna V.
ENG: For the first time, a study of the design has been conducted, and a detailed weight summary of the hot helium pressurization system for an oxidizer tank of the first stage of a launch vehicle (LV) has been presented; the propulsion system of this LV uses boiling oxygen — RG-1 as propellants. The oxidizing generator gas was considered as the heat exchanger heat carrier. The weight of this system was also evaluated for an alternative common heat carrier — reduced generator gas. A good correlation was shown between the obtained results and known data from other pressurization systems. The efficiency of hot helium pressurization systems is demonstrated in the case of multiple reuses of the first stage of an LV. It is also reasonable to use it for the dual activation of the liquid rocket engine (LRE) of the second stage of an LV. In these cases, arising issues are solved using well-established, proven solutions. However, an analysis of technical literature shows that alternative solutions have not been thoroughly studied. In other cases, considering the high cost, structural complexity, actual low reliability, and lack of weight advantages, the use of hot helium pressurization systems (PS) is hardly justified. This primarily concerns LREs with afterburning of generator gas, where oxidizing gas is used as the coolant in the heat exchanger. It is also noted that it is necessary to provide helium reserves on board of the LV and to introduce a gas pressure regulation system in the tank. This is due to the large variations in pressurization path resistance and helium temperatures after the heat exchanger at the design stage. The result is an increase in the calculated gas pressure in the tank, leading to an additional weight increase of 5–8%. It is shown that helium reserves can be easily adjusted based on the results of the first flight tests, whereas reducing the thickness of the tank walls and the diameter of the hot pressurization pipelines with thermal compensators is extremely problematic.
Features of the Swelling Kinetics of Polymer Materials in Blended Diesel Fuel
(Lviv Polytechnic National University, Lviv, 2024) Shevchenko, Olena; Popytailenko, Daryna; Ebich, Yurii; Zamikula, Kostiantyn; Sukhyi, Kostiantyn M.; Vytrykush, Nataliya
ENG: The work is devoted to determining the features of the swelling kinetic patterns of polymer materials in contact with blended fuel containing fatty acid esters. Kinetic equations for predicting the behavior of polymer materials in contact with blended fuel at different temperatures were obtained. Peculiarities of the swelling kinetics of polymer materials with different chemical structures in blended diesel fuel were studied. It was found that the process proceeds in two stages for any temperature conditions. The effect of fatty acid esters in the composition of blended diesel fuel on the stability of polymer materials depending on their structure and temperature factor was determined. An approach to the selection of polymer materials resistant to the effects of fatty acid esters is proposed. The patterns of changes in the swelling resistance of polymer materials upon contact with blended diesel fuel, depending on their structure, were determined.