A method on aerodynamic theory of two-dimensional intake in an incompressible inviscid flow is developed. Conformal mapping and modified THEODORSEN-GARRICK transformation are used. Then the method is extended easily to two-dimensional airfoils in ground effect. This method is essentially accurate especially near the leading and trailing edges without special considerations needed often by other methods. Stream line patterns are easily calculated as well as velocity distribution on the wing surface. Computation time required by this method may be substantially less than other methods.
Using the seamless models fabricated by centrifugal casting, the behavior of cylindrical shells is observed. The high static buckling loads show that the models are nearly perfect. The dynamic load is applied to the shells by means of powder pushers, and a high speed camera is used to take moire-topographic pictures of deformation pattern. The high speed pictures (about 2, 500fps) point out that there exist two typical responses of the shells. One is the case where the axisymmetric deformation pattern is generated first and then the asymmetric one follows, which is the ideal and perfect case. The other is practically typical case where the axisymmetric pattern is not observed but the asymmetric one only is generated locally and then spreads all over the surface of the shells.