NUMERICAL INVESTIGATION OF X-45A TYPE UNMANNED COMBAT AIR VEHICLE

Yıl 2022, Cilt: 27 Sayı: 2, 847 - 856, 31.08.2022

Hacı Soğukpınar , Serkan Cag

https://doi.org/10.17482/uumfd.1094987

Öz

In this paper, the low-speed aerodynamic performance of unmanned combat air vehicle (UCAV) X-45 delta wing was investigated by a numerical method using computational fluid dynamic approaches (CFD). The investigation was conducted with X-45 and the formation of leading-edge vortices (LEV) and vortex breakdown was studied by a varying angle of attack with the range of 5° to 30° at the Reynolds number of 10,000 using the SST turbulence model and are compared with experimental data to validate simulation accuracy of CFD. Stall conditions happened at around 30°, averaged vorticity layer demonstrates a prolonged form that goes along by narrow recirculation zones neighboring to the wing surface. Detail about flow field, including LEV formation, vortex breakdown, interaction, and nonlinear aerodynamic characteristics of X-45 was presented and discussed.

Anahtar Kelimeler

LEV, CFD, delta wing, X-45

X-45A Tipi İnsansız Muharebe Hava Aracının Nümerik Olarak İncelenmesi

Öz

Bu çalışmada, insansız savaş hava aracı (SİHA) X-45 delta kanadının düşük hızlı aerodinamik performansı hesaplamalı akışkanlar dinamiği yaklaşımları (HAD) kullanılarak sayısal bir yöntemle incelenmiştir. İnceleme X-45 ile yürütülmüş ve öncü girdapların (LEV) oluşumu ve girdap kırılması, SST türbülans modeli kullanılarak Reynolds sayısı 10.000'de 5° ila 30° aralığında değişen bir hücum açısı ile incelenmiştir. CFD'nin simülasyon etkinliğini doğrulamak için daha önceden yapılan deneysel verilerle karşılaştırılmıştır. Stol koşulları yaklaşık 30°'de meydana gelmiş, ortalama girdap katmanı, kanat yüzeyine komşu dar döngüsel bölgeleri boyunca uzanan uzun bir form göstermektedir. LEV oluşumu, girdap bozulması ve etkileşimi ve X-45'in doğrusal olmayan aerodinamik özellikleri dahil olmak üzere akış alanı hakkında ayrıntılar sunulmuş ve tartışılmıştır. 

Anahtar Kelimeler

LEV, CFD, delta kanat, X-45

Kaynakça

• 1. Lambourne, N.C., and Bryer, D.W. (1961). The Bursting of Leading-Edge Vortices – Some observations and Discussion of the Phenomenon. ARC R&M 3282.
• 2. Sarpkaya T. (1971) Vortex breakdown in swirling conical flows. AIAA J:9(9):1792±9.
• 3. Faler J.H., Leibovich S. (1978) An experimental map of the internal structure of a vortex breakdown. J Fluid Mech;86(2):313±35.
• 4. Sahin, B., Tasci, M. O., Karasu, I., & Akilli, H. (2017). Flow structures in end-view plane of slender delta wing. In EPJ Web of Conferences (Vol. 143, p. 02099). EDP Sciences.
• 5. Canpolat C., Yayla S., Sahin B., Akilli, H (2012). “Observation of the Vortical Flow over a Yawed Delta Wing”, Journal of Aerospace Engineering, Vol.25, pp. 613-626.
• 6. Yaniktepe, Bulent, Coşkun Ozalp, And Cetin Canpolat. (2016) Aerodynamics and Flow Characteristics of X-45 Delta Wing Planform." Kahramanmaras Sutcu Imam University Journal of Engineering Sciences 19.1: 1-10.
• 7. Swan, Sarah (2006). X-45A Unmanned Combat Vehicle on Display. Aerotech News and Review.
• 8. Elkhoury, M., Yavuz, M. M. and Rockwell, D., (2005). Near-Surface Topology of a Unmanned Combat Air Vehicles Planform: Reynolds Number Dependence. Journal of Aircraft, Vol. 42, No. 5, pp. 1318-1330.
• 9. Canpolat C., Yayla, S., Sahin, B., and Akilli, H. (2009). Dye Visualization of the Flow Structure over a Yawed Nonslender Delta Wing, Journal of Aircraft ,Vol. 46, No. 5.
• 10. Yaniktepe, B., and Rockwell, D. (2004). Flow Structure on a Delta Wing of Low Sweep Angle AIAA Journal, Vol. 42, No. 3.
• 11. F.R. Menter, (1994) Two-Equation Eddy-Viscosity Turbulence Models for Engineering Applications, AIAA Journal, vol. 32, no. 8.
• 12. F.R. Menter, M. Kuntz, and R. Langtry, (2003) Ten Years of Industrial Experience with the SST Turbulence Model, Turbulence Heat and Mass Transfer, vol. 4.
• 13. Sogukpinar, H. (2019) Numerical Investigation of Influence of Diverse Winglet Configuration on Induced Drag. Iranian Journal of Science and Technology, Transactions of Mechanical Engineering 1-13.
• 14. Sogukpinar, H. (2018). Numerical Calculation of Wind Tip Vortex Formation for Different Wingtip devices. INCAS Bulletin, 10(3).
• 15. Sogukpinar, H. (2019) Low speed Numerical Aerodynamic Analysis of New Designed 3D transport Aircraft. International Journal of Engineering Technologies, 4(4), 153-160.
• 16. COMSOL CFD module user guide. http://www.comsol.com. (Access time: February 2022).
• 17. Cummings, Russell M., Scott A. Morton, and Stefan G. Siegel. (2008) Numerical prediction and wind tunnel experiment for a pitching unmanned combat air vehicle. Aerospace Science and Technology 12.5 355-364.