Ground boundary layers effect on aerodynamic coefficients of a compound wing with respect to design parameters

The ground viscous effect is an objective that could be an essential parameter for the conceptual design of wing-in-ground effect (WIG) crafts. This study numerically investigates the effect of ground boundary layers on the aerodynamics of a compound wing of a WIG craft. Computational simulations were conducted to evaluate various design parameters such as middle span size, anhedral angle and taper ratio. The flow structure in the physical domain around the wing surface was demonstrated with a realizable k-ε turbulent model. The numerical results of the compound wing for a fixed ground boundary condition were then further validated using experimental data from the wind tunnel. The principal aerodynamic coefficients of compound wings were achieved for both fixed and moving ground conditions. The numerical simulations demonstrated that the ground viscous effect of fixed ground has some effects on lift and drag coefficients and lift-to-drag ratio, including a reduction in the lift coefficient and an increase in the drag coefficient compared with the moving ground. However, the design parameters had a different impact on the ground viscous effect. Nevertheless, the results are predicted to be able to provide a more fine-grained understanding on the ground viscous effect on WIG craft.