Developing neural network approximator for critical half-opening angle determining in the effect of lift coefficient sign changing for blunted conical bodies

DOI: 10.34759/TRD-2021-119-07

Аuthors

Vasilenko D. A.^*, Dorofeev F. E.^**, Dorofeev E. A.^***

Moscow Institute of Physics and Technology (National Research University), 9, Institutskiy per., Dolgoprudny, Moscow region, 141701, Russia

*e-mail: vasilenko.da@phystech.edu
**e-mail: dorofeev.fe@phystech.edu
***e-mail: edorofeev@mail.ru

Abstract

The sign changing effect of the lifting force while the angle of attack changing in the high speed flat streams for the wedge was first discovered in the V.S. Galkin and A.A. Gladkov work in 1961. This effect in a free-molecular flow was found by V. S. Galkin in 1962. He showed that while the wedge flow-around by the free-molecular gas flow such critical one-half angle exists that at large angles the wedge lifting force became negative at any angle of attack. Moreover, this effect is being manifested at any gas velocities and the ratio of the wedge and gas surface temperatures. The presented work deals with this effect studying for the bodies in the form of squeezed blunted cones. The effect is being studied for the rarefied gas flow without supposition on the free-molecular flow-around mode.

At present, neural-network approximators application for fast computing of aircraft aerodynamic characteristics becomes one of new and promising trends of computational aerodynamics. The dependence of critical one-half angle of the squeezed blunted wedge on the flow geometry and parameters was studied using the approximation based on the hypothesis of locality. The exact neural-network approximator, allowing compute the critical angle at any set of parameters, was developed based on the computed examples of this functional dependence.

Aerodynamic forces acting on the blunted squeezed cone in the rarefied gas stream are being calculated. The article demonstrates that there is such an angle of the cone one-half angle, at which increase the lifting force becomes negative at an arbitrary angle of attack. The values of this critical angle were found for various geometries of the conic body and the Reynolds number of a high-speed flow.

Keywords:

aerodynamic forces in rarefied gas, Reynolds number, gas rarefaction effects, neural networks

References

1. Galkin V.S., Gladkov A.A. Prikladnaya matematika i mekhanika, 1961, vol. XXV, no. 6, pp. 1138 — 1139.

2. Galkin V.S. Prikladnaya matematika i mekhanika, 1962, vol. XXVI, no. 3, pp. 567.
3. Dorofeev E.A., Sviridenko Yu.N. Trudy TsAGI № 2655, Zhukovskii, TsAGI im. prof. N.E. Zhukovskogo, 2002, pp. 156 — 159.
4. Dorofeev E.A., Sviridenko Yu.N. XXV nauchno-tekhnicheskaya konferentsiya po aerodinamike: sbornik trudov, Zhukovskii, Izd-vo TsAGI im. N.E. Zhukovskogo, 2014, pp. 124 — 125.
5. Dorofeev F.E., Dorofeev E.A. Trudy MFTI, 2020, vol. 12, no. 2 (146), pp. 141 — 149.
6. Galkin V.S., Erofeev A.I., Tolstykh A.I. Trudy TsAGI № 1833, Zhukovskii, TsAGI im. prof. N.E. Zhukovskogo, 1977, pp. 6 — 10.
7. Nikolaev V.S. Uchenye zapiski TsAGI, 1981, vol. XII, no. 4, pp. 143 — 150.
8. Kogan M.N. Dinamika razrezhennogo gaza (Dynamics of rarefied gas), Moscow, Nauka, 1967, 440 p.
9. Koshmarov Yu.A., Ryzhov Yu.A. Prikladnaya dinamika razrezhennogo gaza (Applied dynamics of rarefied gas), Moscow, Mashinostroenie, 1977, 184 p.
10. Gusev V.N., Erofeev A.I., Klimova T.V., Perepukhov V.A., Ryabov V.V., Tolstykh A.I. Trudy TsAGI № 1855, Zhukovskii, TsAGI im. prof. N.E. Zhukovskogo, 1977, pp. 43.
11. Egorov I.V., Erofeev A.I. Uchenye zapiski TsAGI, 1997, vol. XXVIII, no. 2, pp. 23 — 40.
12. Vyong Van T’en, Gorelov S.L. Trudy MAI, 2018, no. 100. URL: http://trudymai.ru/eng/published.php?ID=93327
13. Berezko M.E., Nikitchenko Yu.A., Tikhonovets A.V. Trudy MAI, 2017, no. 94. URL: http://trudymai.ru/eng/published.php?ID=80922
14. Ryzhov Yu.A., Nikitchenko Yu.A., Paramonov I.V. Trudy MAI, 2012, no. 55. URL: http://trudymai.ru/eng/published.php?ID=30027
15. Bykov L.V., Nikitin P.V., Pashkov O.A. Trudy MAI, 2014, no. 78. URL: http://trudymai.ru/eng/published.php?ID=53445
16. Nikitchenko Yu.A. Trudy MAI, 2014, no. 77. URL: http://trudymai.ru/eng/published.php?ID=52938
17. Vyong Van T’en, Gorelov S.L., Rusakov S.V. Trudy MAI, 2020, no. 110. URL: http://trudymai.ru/eng/published.php?ID=112844. DOI: 10.34759/trd-2020-110-9
18. Kraiko A.N., Pudovkin D.E., Yakunina G.E. Teoriya aerodinamicheskikh form, blizkikh k optimal’nym (Theory of aerodynamic forms close to optimal), Moscow, Yanus-K, 2001, 132 p.
19. Chernyi G.G. Techenie gaza s bol’shoi sverkhzvukovoi skorost’yu (Gas flow at high supersonic speed), Moscow, Fizmatgiz, 1959, 220 p.
20. Ostapenko N.A., Yakunina G.E. Izvestiya RAN. Mekhanika zhidkosti i gaza, 1992, no. 1, pp. 95 — 106.


Download