الفهرس 
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Abstract
Improving the efficiency of wing-in-ground (WIG) marine craft is challenging. This is due to the lack of information about its performance data and the coupled relation between hydrodynamic and aerodynamic force effects on this craft. Selecting or design of airfoil section is one of the most basic decisions to make in the design of a wing of WIG craft and consequently, the overall efficiency. Early WIG craft used classic wing sections such as the NACA series. These craft were designed for operation in open air rather than close to a ground plane. There are still many aspects of ground effect that need clarification when selecting airfoil section in ground. In the present work, improving the efficiency of WIG craft is discussed throughout modifying the design of wing section. Parameters affecting aerodynamic efficiency of WIG wing are investigated in ground condition by computational fluid dynamic codes. The numerical modeling and its grid are generated using the software GAMBIT. The commercial expert FLUENT is applied for the computational process to simulate the aerodynamic characteristics of airfoil section in ground condition. Various members of the NACA 4-digit airfoil family and other synthetic geometrical shapes are examined in this work. The influences of changing airfoil shape parameters such as, camber, maximum thickness and its location, angle of attack, velocity, and ground clearance on the aerodynamic efficiency are considered in ground condition. New airfoil section shape, suitable to operate efficiently in ground regime is designed different from classic airfoils shape. The proposed airfoil is compared with the classic airfoil NACA 4412. A mathematical model to represent the power prediction for WIG craft is developed, including a detailed analysis of the aerodynamic and hydrodynamic forces acting on the vehicle, and the effect of ground proximity. An iterative computer program is structured using FORTRAN language. The proposed mathematical model is developed to examine the new airfoil sections as an illustrative application. Early take-off from water with about 10 knots (20 %) and decrease in power required to come over take-off resistance with about (30%) is recorded when the classic NACA section is replaced with new airfoil section.