The effect of depth taper on the flexural vibration characteristics of a beam of uniform width is investigated in this paper. The frequency parameters and mode shapes for the first five modes of vibration of tapered beams are presented for a wide range of depth taper. The Euler-Bernoulli equation of a beam is reduced to an eigenvalue problem and its eigenvalues and eigenvectors are obtained by using a digital computer. The theoretical results are compared with those of other authors and with the experimental results.

A simple analysis is presented for the air flow and nozzle power requirements of hovercraft fitted with skirts on which the peripheral jet is blown down the inner skirt face—the “single-wall” type. The theory, which utilises experimental wall-jet data, is applicable to the equilibrium jet state.

A comparison is made with analyses for the air flow and nozzle power requirements of plenum chamber craft and hovercraft fitted with twin-wall skirts. It is concluded that, for a given gap between the skirt bottom and the terrain, at normal operating conditions the order of merit is twin-wall skirt, single-wall skirt, plenum chamber.

This paper presents a summary of a multi-moment method for solving the laminar boundary layer equations. Results obtained with the method tend to converge to the exact values as higher moments are used. Both similar and non-similar external flow fields are considered. The present results are compared with those obtained by another multi-moment method, a finite-difference method and a refined Pohlhausen-type method.

The asymptotic solution, valid near the centre of a rolled-up vortex sheet, obtained by Mangier and Weber, is generalised to include the effects of compressibility. The vortex sheet is taken to be embedded in a potential flow, and the flow field is assumed to be conical.

This paper describes the application of a previously published variational method to the solution of problems of holes in plane elastic sheets and is used to obtain numerical values for the specific case of an elliptic hole in an infinite sheet under tension at infinity. Two kinds of boundary condition at the hole are discussed. The first is that when the hole is unreinforced and stress free, and the second that when the hole is uniformly reinforced by a compact member. The results of the calculations are compared with those from known solutions to the problem, and the accuracy of the present method is investigated. These results provide a useful background to wider application of the method.

Some experiments are described in which an axisymmetric free shear layer attaches to a spherical surface, the exterior flow Mach number ranging from 0-75 to 207. The Chapman-Korst reattachment model is shown to correlate the results very well. The relation between the quantities measured and the numerical predictions of the model is discussed in detail and it is shown that the pressure changes which occur just downstream of reattachment are significantly different from those observed on flat walls.