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Aerodynamic and Stability Characteristics of NACA4412 in Ground Effects

Wang Hao, C. J. Teo, B. C. Khoo, C. J. Goh


The potential increase in aerodynamic efficiency whilst operating in close proximity to the ground has stimulated substantial interests in the design and applications of Wing-In-Ground (WIG) craft. In this paper, the aerodynamic and stability characteristics, such as the Aerodynamic Center of Height (ACH) and the Aerodynamic Center of Pitch (ACP) of a NACA4412 airfoil in GE, are presented. Physical and mathematical definitions of and are given. Both a panel method and a Finite Volume Method (FVM) have been employed to analyze the aerodynamic and stability characteristics in this paper. It is found that for the range of heights and pitch angles investigated, of a NACA 4412 airfoil is only a function of pitch angle while is only a function of height. The  of a NACA4412 airfoil lies behind the. When viscous effects are taken into account, the of the NACA4412 airfoil moves further forwards due to boundary layer de-cambering effects. These findings are important for preliminary WIG-craft analysis.

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