This paper consists of two subjects. First, the influence of streamwisely attached flexible stiffeners on the supersonic flutter of rectangular flat panels was studied analytically with the aid of four terms Galerkin's technique. Numerical calculation has been carried out on a square panel with a single stiffener at the mid-span and has clarified the effect of bending and torsional stiffness of the stiffener. Second, the structural weight alleviation was investigated referring to the authors' previous study. It was assured that the stiffener should be attached spanwisely to the panels of ordinary length-to-width ratio.
In our previous paper, a relationship between the span efficency factors e(λ, ε, 0) for low hemielliptic front view GEW, e(1/λ, ε, 0) for high hemielliptic one and e(1, ε, a=√(1-λ)/(1+λ)) for hemicircular one over a hemi-circular railway was found. Namely e(λ, ε, 0)=e(1/λ, ε, 0)=e(1, ε, a= √(1-λ)/(1+λ)), where λ denotes the height ratio and ε the gap angle parameter. In the present work, we show an explict formula of e for the hemi-circular GEW over a hemi-circular railway, where ε is arbitary and a (radius of railway) is comparatively small. The result obtained is valid to the degree of a4 even if a is assumed to be small.
The span efficiency factor of a hemi-circular front view Ground Effect Wing was obtained exactly by MAMADA and ANDO; the optimum lift distribution, however, was only numerically calculated. In this paper the optimum lift distribution is obtained analytically by using elliptic functions. The total lift and the span efficiency factor are caluculated from this result, which are coincident with those of MAMADA and ANDO.