Studying dependence of “RIGID” aerodynamic models elastic deformations on their geometric and design parameters

DOI: 10.34759/vst-2022-2-45-60

Аuthors

Gorbushin A. R.^1*, Ishmuratov F. Z.^1**, Nguyen V. N.^2***

1. Central Aerohydrodynamic Institute named after N.E. Zhukovsky (TsAGI), 1, Zhukovsky str., Zhukovsky, Moscow Region, 140180, Russia
2. Moscow Institute of Physics and Technology (National Research University), 9, Institutskiy per., Dolgoprudny, Moscow region, 141701, Russia

*e-mail: gorbushin.ar@mipt.ru, gorbushin@tsagi.ru
**e-mail: fanil.ishmuratov@tsagi.ru
***e-mail: vanngok@phystech.edu

Abstract

Aerodynamic models, assumed as a rule to be very rigid, are actually subjected to noticeable elastic deformations under the wind tunnel (WT) testing conditions, which distort the measurement results. The article studies the dependences of elastic deformations of «rigid» WT models on their geometric and structural parameters to develop requirements for the model stiffness characteristics and determine rational modifications of the primary structure, which allow minimizing the model elastic twist angle for various wing layouts and flow-around modes

The procedure specifics for developing a of a steel wing computational model of the aerodynamic model in the NASTRAN software package for solving static aeroelasticity problems are considered. Parametric dependences of elastic deflections, twist angles and the lift coefficient on the wing sweep angle and position of the stiffness axis are studied.

Analysis of the results obtained for the wing model of a typical mainline aircraft reveal the following:

– the elastic streamwise twist angle is mainly determined by the bending angle;

– the angle of torsion around the stiffness axis for the model under consideration increases the streamwise twist angle.

Thus, the streamwise twist would be possible at the twist angle sign changing due to the shift of the axis of stiffness. It may also be seen from the comparative analysis of the center of pressure position of the sections along chord for the three different problems, which correspond to the pressure distribution depending on the curvature and twist at the zero angle of attack, unit angle of attack and these problems combination at different angles of attack.

For the model under consideration, in the middle and end parts, where significant deformations occur, the stiffness axis is located at a distance of (0.4-0.45)c from the leading edge (here с is the wing local chord). The sections’ center of pressure position is much further, and reaches a value of 0.6с at the wing end. This rear position of the pressure center is stipulated by the specificity of the employed supercritical airfoils with a strong undercutting of the lower surface near the trailing edge.

Thus, the possibility of reducing the elastic deformation impact on aerodynamic characteristics for a certain range of wing sweep angles and test modes due to the model layout modification was revealed as the result of parametric studies.

To minimize the elasticity effect on aerodynamic characteristics while WT test, modifications of the model layout may be considered in two aspects: 1) the relative position changing of the pressure centers line and the stiffness axis; 2) torsional stiffness reducing.

The said areas of research are supposed to be developed in the further activities on this issue.

Keywords:

aerodynamic model, wind tunnel, elastic deflection, streamwise twist angle, beam schematization, stiffness axis

References

1. Bisplinghoff R.L., Ashley H., Halfman R.L. Aeroelasticity. Dover Publications, First Dover Edition, 1996, 880 p.

2. Fung Y.C. An introduction to the theory of aeroelasticity. ‎ Dover Publications, 2008, 512 p.

3. Försching H.W. Grundlagen der Aeroelastik. ‎Springer-Verlag, 1974, ‎ 693 p.

4. Amir’yants G.A., Zichenkov M.Ch., Kalabukhov S.I. et al. Aerouprugost’ (Aeroelasticity), Moscow, Innovatsionnoe mashinostroenie, 2019, 651 p.

5. Bezuevskii A.V., Ishmuratov F.Z. Quasi-static deformations effect on aeroelasticity characteristics of an aircraft with high aspect ratio wing. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 14-25.

6. Amir’yants G.A., Efimenko S.V., Sirota S.Ya. Uchenye zapiski TsAGI, 1993, vol. XXIV, no. 1, pp. 131-144.

7. Amiryants G.A., Bunkov V.G., Mamedov O.S., Paryshev S.E. Static and dynamic aeroelasticity study of Boeing wing models. In: “Joint advanced research and technology projects in commercial av iation: 25 years of collaboration between Russian and Boeing scientists (1993-2018)”, Moscow, Nauka, 2017, pp.109-116.

8. Vozhdaev V.V., Teperin L.L. Uchenye zapiski TsAGI, 2018, vol. 49, no. 7, pp. 76-84.

9. Barinov V.A., Pavlenko O.V., Yanin V.V. Uchenye zapiski TsAGI, 2016, vol. 47, no. 3, pp. 80-90.

10. Garifullin M.F., Orlova O.A. Uchenye zapiski TsAGI, 2018, vol. 49, no. 5, pp. 76-85.

11. Vassberg J., Dehaan M., Rivers M., Wahls M. Development of a Common Research Model for Applied CFD Validation Studies. 26^th AIAA Applied Aerodynamics Conference (18-21 August 2008; Honolulu, Hawaii). DOI: 10.2514/6.2008-6919

12. Keye S., Brodersen O., Rivers M.B. Investigation of Aeroelastic Effects on the NASA Common Research Model. AIAA Journal of Aircraft, 2014, vol. 51, no. 4, pp. 1323–1330. DOI: 10.2514/1.C032598

13. Rivers M.B., Dittberner A. Experimental Investigations of the NASA Common Research Model. AIAA Journal of Aircraft, 2014, vol. 51, no. 4, pp. 1183–1193. DOI: 10.2514/1.C032626

14. Rivers M.B., Rudnik R., Quest J. Comparison of the NASA Common Research Model European Transonic Wind Tunnel Test Data to NASA Test Data (Invited). 53rd AIAA Aerospace Sciences Meeting (5-9 January 2015; Kissimmee, Florida). DOI: 10.2514/6.2015-1093

15. Amir’yants G.A., Vermel’ V.D., Ishmuratov F.Z. et al. Uchenye zapiski TsAGI, 2012, vol. 43, no. 3, pp. 88-104.

16. Amir’yants G.A., Ishmuratov F.Z., Kulesh V.P., Naiko Yu.A. Materialy Nauchno-tekhnicheskoi konferentsii “Prochnost’ konstruktsii letatel’nykh apparatov” (31 May – 1 June 2018; Zhukovskii). Ser. “Trudy TsAGI”. Issue No. 2782, Moscow, Izdatel’skii otdel TsAGI, 2018, pp. 179-182.

17. Amir’yants G.A., Vozhdaev V.V., Ishmuratov F.Z. et al. Polet. Obshcherossiiskii nauchno-tekhnicheskii zhurnal, 2013, no. 6, pp. 51–60.

18. Amir’yants G.A., Ishmuratov F.Z., Naiko Yu.A. et al. Uchenye zapiski TsAGI, 2018, vol. 49, no. 5, pp. 65-75.

19. Rybnikov E.K., Volodin S.V., Sobolev R.Yu. Inzhenernye raschety mekhanicheskikh konstruktsii v sisteme MSC.PATRAN-NASTRAN (Engineering calculations of mechanical structures in the MSC.PATRAN-NASTRAN system), Moscow, MIIT, 2003. Part I – 130 p.

20. Rybnikov E.K., Volodin S.V., Sobolev R.Yu. Inzhenernye raschety mekhanicheskikh konstruktsii v sisteme MSC.PATRAN-NASTRAN Engineering calculations of mechanical structures with MSC.PATRAN-NASTRAN system), Moscow, MIIT, 2003. Part II – 174 p.

21. Krutolapov V.E. Ispol’zovanie programmnogo paketa MSC.PATRAN v inzhenernykh raschetakh (MSC.PATRAN software package application in engineering calculations), Tolyatti, TGU, 2008, 116 p.

22. Albano E., Rodden W. A Doublet-Lattice Method for Calculating Lift Distributions on Oscillating Surfaces in Subsonic Flows. AIAA Journal, 1969, vol. 7, no. 2, pp. 279-285. DOI: 10.2514/3.5086

23. Rodden W.P. Theoretical and Computational Aeroelasticity. The Americas Group, Crest Publishing, Camarillo, California, 2011, 814 p.

24. Rodden W.P., Johnson E.H. MSC/NASTRAN Aeroelastic Analysis: User’s Guide, version 68. The MacNeal-Schwendler Corporation. Los Angeles. CA, 1994.

25. Dinamika letatel’nykh apparatov v atmosfere. Terminy, opredeleniya i oboznacheniya, GOST 20058–80 (Aircraft dynamics in atmosphere. Terms, definitions and symbols, State Standard 20058–80), Moscow, Standarty, 1981, 52 p.

26. Mikeladze V.G., Titov V.M. Osnovnye geometricheskie i aerodinamicheskie kharakteristiki samoletov i raket. Spravochnik (The main geometric and aerodynamic characteristics of aircraft and missiles. Handbook), Moscow, Mashinostroenie, 1982, 149 p.