Aerodynamic Performance Assessment of various NACA Airfoils on a Low Aspect Ratio Wing-in-Ground-Effect (WIGE)

Öz

The “ground-effect” is a phenomenon that occurs while aerial vehicles perform flights close to the ground. In case of wing-in-ground-effect (WIGE) aircraft, flight completely consist of operations subjecting to the ground-effect and require special aerodynamic considerations during the design of the vehicle. WIGE aircraft practically bases on the idea of benefiting this effect, therefore the wing, and correspondingly airfoil is the most important geometry to be precisely designed or selected from the beginning of the conceptual design. The objective of this study is to obtain, assess and compare the aerodynamic characteristics of various NACA airfoils in ground-effect with a conceptual design perspective. To this end, a low aspect ratio wing (AR=1.5) was selected as the baseline model and aerodynamic investigation of the design carried out using a Vortex Lattice Method (VLM) solver, comparing and validating with experimental wind tunnel data at Reynold number of 3.4x105. A gird independence study was also carried out to ensure the results were independent from number of panel elements. Subsequently, the airfoils that have been previously known to be used on aerial vehicles (NACA 4412, NACA 23015, NACA 63-415 and NACA 65(2)-215) were applied on the same wing model and analyzed at various ground clearances (h/c) employing the same numerical methodology. The aerodynamic performances of the airfoils were compared in terms of their lift coefficient, drag coefficient and lift-to-drag ratio characteristics.

Anahtar Kelimeler

• Aerodynamics
• NACA
• Airfoil
• Low aspect ratio
• Wing
• Ground effect

Çeşitli NACA Kanat Profillerinin Düşük En-Boy Oranlı Yer Etkisinde Kanat (WIGE) Üzerinde Aerodinamik Performans Değerlendirmesi

Öz

“Yer etkisi”, hava araçları yere yakın uçuşlar gerçekleştirirken ortaya çıkan bir olgudur. Yer etkisinde kanatlı (WIGE) hava araçlarında ise, uçuş tamamen yer etkisinde operasyonlardan oluşur ve hava aracının tasarımı sırasında özel aerodinamik hususların dikkate alınması gerekir. WIGE hava aracı temel olarak bu etkiden faydalanma prensibine dayanır, bu nedenle kanat ve buna bağlı olarak kanat profili, kavramsal tasarımın başlangıcından itibaren hassas bir şekilde tasarlanması veya seçilmesi gereken en önemli şekildir. Bu çalışmanın amacı, çeşitli NACA kanat profillerinin yer etkisindeki aerodinamik özelliklerini kavramsal bir tasarım perspektifiyle elde etmek, değerlendirmek ve karşılaştırmaktır. Bu amaçla, düşük en-boy oranlı bir kanat (AR=1.5) temel model olarak seçilmiş ve tasarımın aerodinamik incelemesi Girdap Kafes Metodu (VLM) çözücüsü kullanılarak, 3.4x105 Reynold sayısında deneysel rüzgâr tüneli testi verileriyle karşılaştırılarak ve doğrulanarak gerçekleştirilmiştir. Sonuçların panel eleman sayısından bağımsız olmasını sağlamak için bir ağdan bağımsızlık çalışması da gerçekleştirilmiştir. Ardından, daha önce hava araçlarında kullanıldığı bilinen kanatlar (NACA 4412, NACA 23015, NACA 63-415 ve NACA 65(2)-215) aynı kanat modeline uygulanmış ve aynı sayısal metodoloji kullanılarak çeşitli yer açıklıklarında (h/c) analiz edilmiştir. Kanatların aerodinamik performansları taşıma katsayısı, sürükleme katsayısı ve taşıma-sürükleme oranı özellikleri açısından karşılaştırılmıştır.

Anahtar Kelimeler

• Aerodinamik
• NACA
• Kanat profili
• Düşük açıklık oranı
• Kanat
• Yer etkisi

Kaynakça

1. 1]. Abu Salem, K., Palaia, G., Chiarelli, M. R., Bianchi, M. 2023. A simulation framework for aircraft take-off considering ground effect aerodynamics in conceptual design. Aerospace; 10(5), 459. https://doi.org/10.3390/aerospace10050459
2. [2]. Eraslan, Y. 2024. Conceptual design of a novel autonomous water sampling wing-in-ground-effect (WIGE) UAV and trajectory tracking performance optimization for obstacle avoidance. Drones; 8(12): 780. https://doi.org/10.3390/drones8120780
3. [3]. Lee, T., Lin, G. 2022. Review of experimental investigations of wings in ground effect at low Reynolds numbers. Frontiers in Aerospace Engineering; 1: 975158. https://doi.org/10.3389/fpace.2022.975158
4. [4]. Rozhdestvensky, K.V. 2006. Wing-in-ground effect vehicles. Progress in Aerospace Sciences; 42(3): 211-283. https://doi.org/10.1016/j.paerosci.2006.10.001
5. [5]. Patria, D., Rossi, C., Fernandez, R. A. S., Dominguez, S. 2021. Nonlinear control strategies for an autonomous wing-in-ground-effect vehicle. Sensors; 21(12): 4193. https://doi.org/10.3390/s21124193
6. [6]. Papadopoulos, C., Mitridis, D., Yakinthos, K. 2022. Conceptual design of a novel unmanned ground effect vehicle (UGEV) and flow control integration study. Drones, 6(1): 25. https://doi.org/10.3390/drones6010025
7. [7]. Nirooei, M. 2018. Aerodynamic and static stability characteristics of airfoils in extreme ground effect. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering; 232(6): 1134-1148. https://doi.org/10.1177/0954410017708212
8. [8]. Agarwal, R.K. 2018. Aerodynamics of a transonic airfoil in ground effect. in 6th International Conference and Exhibition on Mechanical & Aerospace Engineering. 2018.

9. [9]. Yin, B., Guan, Y., Wen, A., Karimi, N., Doranehgard, M.H. 2021. Numerical simulations of ultra-low-Re flow around two tandem airfoils in ground effect: isothermal and heated conditions. Journal of Thermal Analysis and Calorimetry; 145: 2063-2079. https://doi.org/10.1007/s10973-020-09987-z
10. [10]. Thianwiboon, M. 2002. Numerical aerodynamic analysis of a reflexed airfoil, N60R, in ground effect with regression models. International Journal of Thermofluid Science and Technology; 9(1): 090105. https://doi.org/10.36963/IJTST.2022090105
11. [11]. Hu, H., Zhang, G., Shi, Y., Zhang, Z., Sun, T., Zong, Z. 2024. Influence of wingspan on aerodynamic properties of rectangular NACA4412 wing in ground effect. Journal of the Brazilian Society of Mechanical Sciences and Engineering; 46(2): 71. https://doi.org/10.1007/s40430-023-04629-5
12. [12]. Wang, Y. 2025. Numerical study on the aerodynamic characteristics of two-dimensional ground effect of an anti-s airfoil. Journal of Physics: Conference Series; 2977: 012040. https://doi.org/10.1088/1742-6596/2977/1/012040
13. [13]. Deperrois, A. 2009. XFLR5 Analysis of foils and wings operating at low Reynolds numbers. Guidelines for XFLR5.
14. [14]. Jung, K.H., Chun, H.H., Kim, H.J. 2008. Experimental investigation of wing-in-ground effect with a NACA6409 section. Journal of Marine Science and Technology; 13: 317-327. https://doi.org/10.1007/s00773-008-0015-4
15. [15]. Suh, S.B., Jung, K.-H., Chun, H.-H. 2011. Numerical and experimental studies on wing in ground effect. International Journal of Ocean System Engineering; 1(2): 110-119. https://doi.org/10.5574/IJOSE.2011.1.2.110
16. [16]. Eraslan, Y. 2023. Validation of a numerical method for aerodynamic performance estimation of wing-in-ground-effect. In: Bardak S (ed) International research and reviews in engineering, Volume I, pp 109-121.
17. [17]. Thianwiboon, M. 2023. A Numerical comparative study of the selected cambered and reflexed airfoils in ground effect. Engineering Journal; 27(11): p. 39-51. https://doi.org/10.4186/ej.2023.27.11.39
18. [18]. Hadi Doolabi, M., Bakhtiarifar, M., Sadati, H. 2024. Experimental study of airfoil aerodynamic behavior under oscillating motion in ground effect. Journal of Applied Fluid Mechanics; 17(11): p. 2411-2423. https://doi.org/10.47176/jafm.17.11.2596
19. [19]. Nelson, R.C. Flight Stability and Automatic Control. Press: WCB/McGraw Hill New York, 1998.