Studying working process of the low-pressure compressor at the windmill modes

DOI: 10.34759/vst-2023-2-91-98

Аuthors

Rozhkova M. V.

Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia

e-mail: rozhkova_margarita@bk.ru

Abstract

The engine cut-off may occur in flight in a number of cases such as compressor surging, a bird ingress, or the crew error. In spite of the fact that the engine cut-off does not occur frequently, the possibility of its restarting in flight is one of the certification requirements, and comprehension of axial turbo-machines operation and characteristics at the extremely off-design modes gains more and more significant importance.

Following the engine cut-off in flight, rotation frequency of the engine rotors decreases to the steady-state value called the windmill rotation speed n_windmill. The compressor rotates herewith due solely to the impact pressure of the air incoming to the engine (the combustion chamber is off, the engine does not produce power). There is free windmilling, as well as locked wingmilling (the auto wingmilling at the rotor cranking by the starter). In the first case, which is being considered in the article, the engine shafts rotate with the speed depended on the flight Mach number, friction losses, angle of attack, the flow separation etc. In the second case, the initial shaft rotation is hampered since the ram air creates a torque not enough for the rotor cranking. At the modes where the speed is lower than at the rated idle compressor may run as a compressor (the energy is being transferred from the rotor to the liquid, which leads to the total pressure and temperature increase), a stirrer (total temperature rises in the compressor, but the total pressure falls), of a turbine (the temperature and pressure at the outlet are lower than at the inlet, and the power is being taken off the flow).

Numerical modeling in the 3D setting to obtain the subsonic ventilator characteristics at the windmill modes of was performed with the software complexes FlowVision 3.12.01 and NUMECA Fine Turbo 8.9.1 using the Spalart-Allmaras (SA) turbulence model. The simulation was performed for the following flight mode: the flight altitude of 11 000 m, and Mach number of 0.2–0.6.

The availability of the engine subassemblies characteristics is necessary to elaborate a technique for the parameters estimation of the turbojet engine at the windmill modes. As for now, there are no exact mathematical models allowing reliable description of these modes.

The purpose of this work consists in developing a technique for creating characteristics of a low-pressure compressor in windmill modes. Further research will be aimed at obtaining performances of turbines and other engine subassemblies as well as the development of the above-mentioned technique.

Keywords:

gas turbine engines windmilling, axial-flow compressor, compressor head-capacity characteristic, turbine operation of the compressor, rotor speed

References

1. Novosl’tsev. Rrabochii protsess kompressorov v sisteme GTD na rezhimakh avtorotatsii (Compressors workflow within the gas turbine engine system at autorotation modes). Ph.D thesis, Omck, OmGTU, 2002, 182 p.
2. Barsukov S.I., Kuznetsov V.I. Avtorotatsiya gazoturbinnykh dvigatelei (Windmilling of gas turbine engines), Irkutsk, Irkutskii universitet, 1983, 91 p.
3. Daineko V.I. Vestnik dvigatelestroeniya, 2006, no. 3, pp. 17-20.
4. Ferrer-Vidal L.E., Pachidis V., Tunstall R.J. An enhanced compressor sub-idle map generation method. Proceedings of GPPS Forum (10-12 January 2018, Zurich).
5. Ezrokhi Y.A., Gusmanova A.A. On accounting for turbine efficiency, while gas turbine engine parameters determining. Aerospace MAI Journal, 2022, vol. 29, no 2, pp. 77-87. DOI: 10.34759/vst-2022-2-77-87
6. Bakulev V.I., Golubev V.A., Krylov B.A. Teoriya, raschet i proektirovanie aviatsionnykh dvigatelei i energeticheskikh ustanovok (Theory, calculation and design of aircraft engines and power plants), Moscow, MAI, 2003, 688 p.
7. Kholshchevnikov K.V. Teoriya i raschet aviatsionnykh lopatochnykh mashin (Theory and calculation of aviation impeller machines), Moscow, Mashinostroenie, 1970, 610 p.
8. Alabin M.A., Kats B.M., Litvinov Yu.A. Zapusk aviatsionnykh ga-zoturbinnykh dvigatelei (Launch of aviation gas turbine engines), Moscow, Mashinostroenie, 1968, 228 p.
9. Morozov A.A., Ilyukhin S.N., Khlupnov A.I. Autorotation application analysis for the safe-landing field-tests. Aerospace MAI Journal, 2020, vol. 27, no 2, pp. 185-195. DOI: 10.34759/vst-2020-2-185-195
10. Kuznetsov V.V. Osnovy teorii sudovykh turbomashin (Bases of the theory of marine turbomachines), Moscow, Infa-M, 2019, 176 p.
11. Gorelov A.P. Ekspluatatsiya korabel’nykh gazoturbinnykh ustanovok (Operation of ship gas turbine plants), Moscow, Voenizdat, 1972, 310 p.
12. Dunyashev D.A., Goldovskii A.A., Pravidlo M.N. Design problems of a small-size unmanned aerial vehicle launching system by free fall method. Aerospace MAI Journal, 2022, vol. 29, no. 1, pp. 27-35. DOI: 10.34759/vst-2022-1-27-35
13. Kuznetsov V.I. «Problemy i perspektivy razvitiya dvigatelestroeniya». Sbornik statei Samara, Vestnik SGAU, 2003. Part II, pp. 116-122.
14. Kuznetsov V.I. Omskii nauchnyi vestnik, 2002, no. 20, pp. 123-124.
15. Daineko V.I. Aviatsionnaya tekhnika, 1986, no. 4, pp. 84-86.
16. Zachos P.K. Gas Turbine Sub-idle Performance Modelling: Altitude Relight and Windmilling. D. Thesis. UK, Cranfield University, 2010, 239 p.
17. Riegler C., Baue, M., Kurzke J. Some aspects of modeling compressor behavior in gas turbine performance c Journal of Turbomachinery, 2001, vol 123(2), pp. 372-378. DOI: 10.1115/1.1368123
18. Leshchenko I.A., Vovk M.Yu., Burov M.N. Obshcherossiiskii nauchno-tekhnicheskii zhurnal, 2022, no. 7, pp. 36-44.
19. Zachos P.K., Aslanidou I., Pachidis V., Singh, R. A sub-idle compressor characteristic generation method with enhanced physical background. Journal of Engineering for Gas Turbine and Power, 2011, vol. 133, no. 8: 081702. DOI: 10.1115/1.4002820
20. FlowVision 3.12.01 User Manual, Moscow, TESIS, 2020, 1547 p.
21. Baturin O.V., Kolmakova D.A., Matveev V.N., Popov G.M. Raschetnoe opredelenie kharakteristik stupeni kompressora s pomoshch’yu metodov vychislitel’noi gazovoi dinamiki (Computational determination of compressor stage performances by means of computational gas dynamics methods), Samara, SGAU, 2013, 64 p.