Problem of the Unsteady Motion of a Wing at Variable Distances from a Ground-Plane Surface.

摘要

An examination is made of the problem of determining the motion of a wing flying at variable distances from a ground-plane surface. Considered in succession are the two-and three-dimensional problems for a wing near such a surface in an ideal incompressible fluid at a given horizontal velocity and for a certain vertical velocity in a spatially fixed coordinate system and, as well, for a coordinate system linked to the wing. It is concluded that the ground has a considerable effect on the unsteady characteristics of the wing during takeoff and landing, resulting in an appreciable variation of the lift and of the stability characteristics. (Author)