Experimental studies of the influence of elastic-dissipative parameters of engine mounting units on the dynamic characteristics of the “wing model – elastic pylon – engine” system

A feature of modern heavy transport aircraft is their layout with engines on elastic pylons under the wing, with the fuel tanks located in the wing consoles. In this case, the main elastic tones of the aircraft’s own oscillations, which determine its dynamic response to external disturbing influences, include the so-called motor tones (vertical and horizontal (lateral) oscillations of engines on elastic pylons). A new type of flutter has appeared – pylon, which for some aircraft determines the critical flutter speed of the aircraft as a whole. The main reason for this phenomenon is the low oscillation damping of the engine on the pylon under the wing. Therefore, research aimed at modernizing the engine mounting points on the pylon in order to reduce the level of elastic oscillations during aircraft operation seems relevant. One of the possible ways to solve this problem is to use the concept of a freed engine, when the engine attachment points to the pylon are modernized, providing more effective damping of engine oscillations. In order to confirm the possibility of practical implementation of these solutions, corresponding experimental studies were carried out on an experimental setup developed by the authors. A design of engine mounting units has been developed that allows specified displacements of the engine relative to the pylon during forced elastic oscillations of the system, which includes a hinged suspension, installation of additional elastic elements and hydraulic dampers.The article presents the results of studies of the influence of elastic-dissipative parameters (partial frequency of natural oscillations and partial decrement of oscillations) of an engine mount on an elastic pylon on the dynamic characteristics of the dynamic system “wing model – elastic pylon – engine”. It is shown that by introducing specially designed engine suspension units on pylons, it is possible to significantly change the dynamic characteristics (frequencies and amplitudes of natural oscillations) of the elastic system as a whole. Thus, the amplitudes of oscillations of the engine’s center of mass in the region of motor tones decrease by 3...7 times during forced harmonic oscillations.

1. Jorgensen L., Saki H. Design of aero engine structure. Bachelor’s thesis. University West. Uppsala, Sweden, 2023. 65 p.

2. Зиченков М.Ч., Ишмуратов Ф.З., Кузнецов А.Г. Исследование совместного влияния гироскопических сил и конструкционного демпфирования на характеристики флаттера крыла аэроупругой модели EuRAM // Вестник МАИ. 2018. Т. 25, № 4. С. 86–95.

3. Овчинников В.В., Петров Ю.В. Численные методы исследования аэроупругости летательных аппаратов: монография. М.: ИД Академии имени Н.Е. Жуковского, 2017. 160 с.

4. Овчинников В.В., Петров Ю.В. Исследование влияния инерционных и гироскопических свойств работающих двигателей на прочностные характеристики динамической системы двигатель-пилон-крыло // Научный Вестник МГТУ ГА. 2020. Т. 23, № 3. С. 63–72. DOI: 10.26467/2079-0619-2020-23-3-63-72

5. Fujino M., Oyama H., Omotani H. Flutter characteristics of an over-the-wing engine mount business-jet configuration // 44th AiAA/ASME/ASCE/AHS Structures, Structural Dynamics and Materials Conference. AIAA 2003-1942, 2003. Pp. 1–12. DOI: 10.2514/6.2003-1942

6. Waitz S., Hennings H. The aeroelastic impact of engine thrust and gyroscopics on aircraft flutter instabilities // International Forum on Aeroelasticity and Structural Dynamics. IFASD-2015. Russia, Saint Petersburg, 2015. Pp. 1–15.

7. Wang L. Aeroelastic modeling and analysis of the wing/engine system of a large aircraft / L. Wang, Z. Wan, Q. Wu, Ch. Yang // Procedia Engineering. 2012. Vol. 31. Pp. 879–885. DOI: 10.1016/j.proeng.2012.01.1116

8. Zettel S., Boswald M., Winter R. Jetengine vibration model for the estimation of pylon-wing interface loads // DAGA. 2023. Pp. 628–631.

9. Вермель В.Д. Результаты исследований опытного образца механического демпфера вибраций с вращательными парами трения / В.Д. Вермель, М.Ч. Зиченков, А.Н. Корякин, С.Э. Парышев // Вестник Концерна ВКО «Алмаз – Антей». 2020. № 4 (35). С. 77–86. DOI: 10.38013/2542-0542-2020-4-77-86

10. Серов М.В., Аверьянов Г.М., Александрова С.Г. Опыт применения теории колебаний к практическим вопросам применения инерционных динамических гасителей колебаний // Известия МГТУ «МАМИ». 2013. Т. 3, № 1 (15). С. 118–124.

11. De Silva C.W. Vibration damping, control, and design. 1st ed. CRC Press, 2007. 634 p.

12. Ünker F., Çuvalci O. Vibration control of a column using a gyroscope // Procedia-Social and Behavioral Sciences, 2015. Vol. 195. Pp. 2306–2315. DOI: 10.1016/j.sbspro.2015.06.182

13. He H., Xie X., Wang W. Vibration control of tower structure with multiple cardan gyroscope [Электронный ресурс] // Shock and Vibration. 2017. Vol. 2017. Article ID 3548360. 11 pp. DOI: 10.1155/2017/3548360 (дата обращения: 03.09.2023).

14. Soleymani M., Norouzi M. Active gyroscopic stabilizer to mitigate vibration in a multimegawatt wind turbine [Электронный ресурс] // Wind Energy. 2021. Vol. 24, iss. 7. Pp. 720–736. DOI: 10.1002/we.2599 (дата обращения: 03.09.2023).

15. Ситников Д.В., Бурьян А.А. Система виброизоляции с активным динамическим гасителем колебаний при нестационарном режиме работы поршневой машины // Омский научный вестник. 2021. № 4 (178). С. 13–17. DOI: 10.25206/1813- 8225-2021-178-13-17