Numerical investigation on aerodynamics of NACA 4412 under wavy ground

Öz

Improving knowledge of aerodynamic effects of wavy ground is essential especially for the development of stability and control strategies, for design improvements in the wider application of ground-effect aircraft such as ekranoplans, seaplanes and airfish-8. In this study, the aerodynamic (lift, drag and pitching moment) behavior of NACA 4412 airfoil under the effect of wavy ground was investigated with URANS CFD. The effects of different angles of attack, wavelengths, wave amplitudes and ground clearance were analyzed. While the airfoil was kept in a fixed position, wave motion in sinusoidal form was defined at the lower boundary and calculations were made by sliding mesh method. The results obtained revealed that at high angles of attack, the aerodynamic coefficients (C_L, C_D, C_M) became more sensitive to the wave parameters and the periodic fluctuations increased. Higher oscillations in lift and drag forces and moment have been observed, especially in short wavelength, high wave amplitude, and low ground clearance configurations. In addition, optimal parameter combinations are also proposed to improve aerodynamic performance in wavy ground conditions. 

Anahtar Kelimeler

• Wavy ground
• NACA 4412
• URANS
• CFD
• Lift
• Drag
• Moment
• Fluctuation
• β metric

Kaynakça

1. [1] Rozhdestvensky K V. Wing-in-ground effect vehicles. Progress in Aerospace Sciences 2006; 42(3): 211–283.
2. [2] Qu Q, Lu Z, Liu P, Agarwal RK. Numerical study of aerodynamics of a wing-in-ground-effect craft. Journal of Aircraft 2014; 51(3): 913–924.
3. [3] Hu H, Ma D. Airfoil aerodynamics in proximity to wavy ground for a wide range of angles of attack. Applied Sciences (Switzerland) 2020; 10(19).
4. [4] Liu X, Ma D, Yang M, Guo Y, Hu H. Numerical study on airfoil aerodynamics in proximity to wavy water surface for various amplitudes. Applied Sciences 2021; 11(9), 4215.
5. [5] Su Y, Li D, Zhao S. Lift augmentation of a circulation control airfoil in proximity to water waves. Journal of Physics: Conference Series, Beihang University, Beijing, China, 2024; 2913(1), 012012.
6. [6] Qu Q, Jia X, Wang W, Liu P, Agarwal RK. Numerical study of the aerodynamics of a NACA 4412 airfoil in dynamic ground effect. Aerospace Science Technology 2014; 38: 56–63.
7. [7] Firooz A, Gadami M. Turbulence flow for NACA 4412 in unbounded flow and ground effect with different turbulence models and two ground conditions: Fixed and moving ground conditions. Int. Conference on Boundary and Interior Layers (BAIL 2006), Göttingen, Germany, 2006.
8. [8] He W, Guan Y, Theofilis V, Li LKB. Stability of low-Reynolds-number separated flow around an airfoil near a wavy ground. AIAA Journal 2019; 57(1): 29–34.

9. [9] Liang H, Zong Z, Zou L. Nonlinear lifting theory for unsteady WIG in proximity to incident water waves. Part 1: Two-dimension. Applied Ocean Research 2013; 43: 99–111.
10. [10] Win SY, Thianwiboon M. Parametric optimization of NACA 4412 airfoil in ground effect using full factorial design of experiment. Engineering Journal 2021; 25(12): 9–19.
11. [11] Nebylov A, Nebylov V, Fabre P. WIG-Craft flight control above the waved sea. IFAC Conference Papers on Line 2015; 48(9); 102–107.
12. [12] Matdaud Z, Zhahir A, Pua’At AA, Hassan A, Ahmad MT. Stabilizing attitude control for mobility of wing in ground (WIG) craft - A Review. IOP Conference Series: Materials Science and Engineering. Institute of Physics Publishing 2019, 705(1), 012038 (Presented at the 5th International Conference on Mechanical, Automotive and Aerospace Engineering 2019).
13. [13] Cui, E., & Zhang, X. (2007). Ground effect aerodynamics. In C. Tropea, A. L. Yarin, & J. F. Foss (Eds.), Springer Handbook of Experimental Fluid Mechanics Springer, 2007; 721–748.
14. [14] Smuts EM, Sayers AT. CFD study of a wing in close proximity to a flat and wavy ground plane. R & D Journal of the South African Institution of Mechanical Engineering 2011; 27: 1-9.
15. [15] Ahmed MR, Takasaki T, Kohama Y. Experiments on the aerodynamics of a cambered airfoil in ground effect. In: Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting. American Institute of Aeronautics and Astronautics Inc. 2006; 3132–3148.
16. [16] Castelli M R, Englaro A, Benini E. The Darrieus wind turbine: Proposal for a new performance prediction model based on CFD. Energy 2011; 36(8): 4919-4934.
17. [17] Du P, Agarwal RK. Drag prediction of NASA common research models using different turbulence models. American Institute of Aeronautics and Astronautics (AIAA) 35th AIAA Applied Aerodynamics Conference, AIAA Aviation Forum, Denver, CO, United States. AIAA, 2017; Paper 2017, 3560.