Numerical investigation on aerodynamics of NACA 4412 under wavy ground

Abstract

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. 

Keywords

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

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