Non-planar wings in non-planar ground effect

A numerical method is developed for solving the problem of a wing in arbitrary non-planar ground effect. The linearized equations of unsteady motion for an arbitrary non-planar wing in non-planar ground effect are presented. Numerical calculations were made to determine all the aerodynamic characteristics and stability derivatives for various thin, uncambered planar and non-planar wings (including two wings connected in tandem) in planar and non-planar ground effect. These calculations were incorporated into the equations of unsteady motion to determine the dynamic stability characteristics of these wings in the various ground effect situations. Several wings were found to be longitudinally stable, but only in rare cases were they found to be laterally stable. An experiment was conducted to compare some of the numerical calculations with reality. The agreement was reasonable.