Abstract. Interest in various active and passive methods of flow control over an airfoil, aimed at increasing the maximum lift coefficient of a wing, is driven by the relevance of reducing take-off and landing distan-
ces. Unlike active flow control methods, which require energy input, passive methods use the energy of the external airflow in such a way as to produce an overall beneficial effect. Passive flow control methods are simpler than active ones, have more reliable designs, and generally add little extra weight.
This work presents a passive method for controlling the flow over a high-lift wing airfoil with a flap by means of specially profiled flow channels. The described control method is effective both with the flap undeflected (cruise flight mode) and with the flap deflected. It is shown that in the profiled channel the airflow acceler-ates and exits tangentially onto the upper surface of the flap, increasing suction and shifting the boundary-layer separation line on the deflected flap downstream. Humid air with increased moisture concentration raises the momentum coefficient of the blown jet.

Keywords: passive flow control method, flap blowing, aerodynamic characteristics of an unmanned aerial vehicle, CFD methods

For citation: Brutyan M. A., Pavlenko O. V., Ye Htun. Numerical study of the influence of passive blowing on the aerodynamic characteristics of a high-lift airfoil in dry and humid air. Aerospace Engineering and Technology. 2025. Vol. 3, no. 4, pp. 584–597. https://doi.org/10.52467/2949-401X-2025-3-4-584-597; https://elibrary.ru/MYDHWH (In Russian)

References
1. Young B. A. Lateral control with high lift devices. R&M. 1951. No. 2583.
2. Petrov A. V. Aerodinamika transportnykh samoletov korotkogo vzleta i posadki s energetich-eskimi sistemami uvelicheniya podyemnoy sily [Aerodynamics of short takeoff and landing transport aircraft with powered lift systems]. Moscow: Innovative Mechanical Engineering, 2018. 736 p. (In Russian)
3. Brutyan M. A., Potapchik A. V., Razdobarin A. M., Slitinskaya A. Yu. Vliyaniye struynykh vikhregeneratorov na vzletno-posadochnyye kharakteristiki kryla s predkrylkom [Influence of jet vortex generators on the takeoff and landing characteristics of a wing with a leading-edge slat]. Vestnik of the Moscow Aviation Institute. 2019. Vol. 26, no. 1, pp. 19–26. https://elibrary.ru/YZYNZR (In Russian)
4. Brutyan M. A., Volkov A. V., Potapchik A. V. Eksperimentalnoye issledovaniye passivnogo sposoba oslableniya transzvukovogo bafeta [Experimental study of a passive method for attenuating transonic buffet]. Letters to the journal of technical physics. 2019, Vol. 45, Issue 21, pp. 19–21. https://doi.org/10.21883/PJTF.2019.21.48467.17881 (In Russian)
5. Abramova K. A., Brutyan M. A., Volkov A. V., Petrov A. V., Potapchik A. V., Suda-kov V. G. Issledovaniya sredstv upravleniya obtekaniyem krylyev magistralnykh samoletov na krey-serskikh rezhimakh poleta [Studies of flow-control devices for wings of long-range aircraft in cruise flight conditions]. TsAGI Proceedings. 2019. Issue 2783, pp. 18–30 (In Russian)
6. Petrov A. V. Energeticheskiye metody uvelicheniya podyemnoy sily kryla [Energy-based methods for increasing wing lift]. Moscow: Fizmatlit, 2011. 402 p. https://elibrary.ru/UGLJMV (In Russian)
7. Tsipenko V. G., Shevyakov V. I. Obespecheniye bezopasnosti poleta vozdushnykh sudov s uchetom novykh sertifikatsionnykh trebovaniy [Ensuring flight safety of aircraft in view of new cer-tification requirements]. Scientific Bulletin of the Moscow State Technical University of Civil Avia-tion. 2019. Vol. 22, no. 3, pp. 45–56. https://doi.org/10.26467/2079-0619-2019-22-3-45-56; https://elibrary.ru/BVORRQ (In Russian)
8. Sha M., Sun Y. Issledovaniye povrezhdeniy orgstekla letatelnykh apparatov v usloviyakh vysokoskorostnogo dozhdevogo kapleudara [Study of acrylic glass damage on aircraft under high-speed rain droplet impact]. Vestnik MAI (Moscow Aviation Institute). 2022. Vol. 29, no. 3, pp. 65–76. https://doi.org/10.34759/vst-2022-3-65-76; https://elibrary.ru/FOWQNE (In Russian)
9. Heymann F. J. On the shock wave velocity and impact pressure in high-speed liquid-solid im-pact. Journal of Fluids Engineering. 1968. Vol. 90, no. 3, pp. 400–402. https://doi.org/10.1115/1.3605114.
10. Shevyakov V. I. Inzhenernyy metod opredeleniya sootvetstviya vozdushnykh sudov sertif-ikatsionnym trebovaniyam dlya usloviy obledeneniya [An Engineering method for determining the compliance of aircraft with certification requirements under icing conditions]. Scientific Bulletin of the Moscow State Technical University of Civil Aviation. 2013. No. 188, pp. 46–52. https://elibrary.ru/QCJITF (In Russian)
11. Brill J., Arirachakaran S. State of the art in multiphase flow. Journal of Petroleum Technolo-gy. 1992. Vol. 44, no. 05, pp. 538–541. https://doi.org/10.2118/23835-PA
12. Issa R. I., Oliveira P. J. Numerical prediction of phase separation in two-phase flow through junctions. Computers Fluid. 1993. Vol. 23, no. 2, pp. 347–372. https://doi.org/10.1016/0045-7930(94)90045-0
13. Walters L. C., Soliman H. M., Sims G. E. Two-phase pressure drop and phase distribution at reduced tee junctions // International Journal of Multiphase Flow. 1998. Vol. 24, no. 5, pp. 775–792. https://doi.org/10.1016/S0301-9322(98)00002-0
14. Bykov L. V., Indrulenayte Ya. A., Pashkov O. A. Resheniye zadachi dozvukovogo obteka-
niya aerodinamicheskoy poverkhnosti dvumfaznym vyazkim szhimayemym potokom s uchetom vzaimodeystviya faz [Solution of the problem of subsonic flow around an aerodynamic surface by a two-phase viscous compressible flow with phase interaction taken into account]. Izvestiya Vysshikh Uchebnykh Zavedenii. Mechanical Engineering. 2018. Vol. 11, no. 704, pp. 68–77. https://doi.org/10.18698/0536-1044-2018-11-68-77; https://elibrary.ru/YOUZDV(In Russian)
15. Shih T. H., Liou W. W., Shabbir A., Zhu J. A New k-e eddy-viscosity model for high reyn-olds number turbulent flows – model development and validatio. Computers Fluids. 1995. Vol. 24, no. 3, pp. 227–238. https://doi.org/10.1016/0045-7930(94)00032-T
16. Wolfshtein M. The velocity and temperature distribution in one-dimensional flow with turbu-lence augmentation and pressure gradient. International Journal of Heat and Mass Transfer. 1969. Vol. 12, no. 3, pp. 301–318. https://doi.org/10.1016/0017-9310(69)90012-X
17. Sidorova L. P. Meteorologiya i klimatologiya: uch. posob. Chast 1 [Meteorology and clima-tology: textbook. Part 1]. Meteorology. Yekaterinburg: UrFU, 2015. P. 19. https://elibrary.ru/YMYHPN (In Russian)