Thickness-Induced Lift on a Thin Airfoil in Ground Effect

Numerical solution of the equation for a thin airfoil in ground effect

“…This does not apply in the case of ground presence. 3 In this case, the dependence of NI and N 2 on £> is given in Figs. 3 and 4. The lift is negative, i.e., the resulting force is toward the ground.…”

Flapping Thin Airfoil Interacting With the Ground

“…The lift change near the ground under the angle of attack α is given with three terms involving h as [1] ) 512…”

“…The physics of the problem necessitates a mathematical modeling with the image vortices to satisfy the tangency boundary condition at the ground. The steady state lift coefficient formula is provided by [1] in series form based on the Keldish-Lavrentiev expansion of the Kernel function as described in [2]. In this series expression of the lift, taking the first term only gives additional lift near the ground, however, adding more terms generate reduction in the lift for the cases where the mean distance to the ground is very small.…”

Design of a wing section in ground effect: application to high speed ground transportation

“…With regard to profiles in ground effect, this method was used by Giesing in Germany in 1964 [312] and 1968 [313] (see discussion in [295]). …”

“…At the time, the usual approach was to split the domain into two distinct regions, the internal underbody region between the ground and the body streamline formed by the wing and its wake, and the external flow region. Since all vertical dimensions were ten percent of chord at most, the external flow region was like a thin-airfoil problem, with the "airfoil" being In the 1980s, the thin-airfoil method was once again utilized to study the case of large ground clearances (see [295], [290] and [296]). …”