The Dynamic Relaxation (DR) method is applied to the solution of geometrically non-linear, elastic, laminated plate, flexural and stability problems. Two categories of plate are considered, namely, those that are symmetrically and unsymmetrically laminated with respect to the plate middle surface. Whereas the former category exhibits a bending – twisting coupling phenomenon, the latter exhibits an extensional – flexural type of coupling. The effects of these coupling phenomena are evaluated by comparing the plate responses with those of corresponding homogeneous, specially orthotropic plates. With the exception of uniaxially compressed plates of the latter category in the post-buckling regime, it is found that for both flexural and stability problems the coupling phenomena cause a reduction in stiffness and the extent of this reduction is dependent on the lay-up of the laminate.

If surface fences are to be applied for measuring skin friction in three-dimensional boundary layers they must be calibrated for both magnitude and direction of the shear stress. Results of the calibration for fences of different height are given. Furthermore, a manufacturing process and a mounting procedure are described to obtain surface fences with identical calibration curves.

Existing effective viscosity models which have been very valuable in the mean field closure method for turbulent boundary layer computation have shown certain undesirable limitations for certain realistic but general boundary layer flows. The more general flows usually involve non-negligible considerations of pressure gradients and such wall conditions as roughness, curvature and aspiration or transpiration in varying degrees of importance. The effects of these external and wall influences have, unfortunately, been underplayed by most existing effective viscosity models. The present model of the effective viscosity is developed for a general flow and has shown remarkable agreement with experimentation, without being any more complex than existing models.

Equations are derived for the total lift about low aspect ratio wings in an inviscid, incompressible, uniform flow. The analysis extends Bollay’s analysis, which followed the line suggested by Prandtl, and it is shown experimentally that Bollay’s simplifying assumptions can still be applied. Agreement is good between the present theory and the author’s experiment for values of total lift with small tip clearance.

Solutions to the problem of separated flow past slender delta wings for moderate values of a suitably defined incidence parameter have been calculated by Smith, using a vortex sheet model. By increasing the accuracy of the finite-difference technique, and by replacing Smith’s original nested iteration procedure, to solve the non-linear simultaneous equations that arise, by a Newton’s method, it is possible to extend the range of the incidence parameter over which solutions can be obtained. Furthermore for sufficiently small values of the incidence parameter, new and unexpected results in the form of vortex systems that originate inboard from the leading edge have been discovered. These new solutions are the only solutions, to the author’s knowledge, of a vortex sheet leaving a smooth surface.

Interest has centred upon the shape of the finite vortex sheet, the position of the isolated vortex, and the lift, and variations of these quantities are shown as functions of the incidence parameter. Although no experimental evidence is available, comparisons are made with the simpler Brown and Michael model in which all the vorticity is assumed to be concentrated onto an isolated line vortex. Agreement between these two models becomes very close as the value of the incidence parameter is reduced.

The integral equation approach to the mixed flow problem of infinite wings at high subsonic speeds is adopted for non-circulatory and circulatory (lifting) flows. The solutions are determined from a system of non-linear algebraic equations and, to ensure always unique solutions, the method of differentiation with respect to a parameter has been applied. The resulting Cauchy problem is then solved with the linearised flow solution as the initial value vector. For the case of embedded shocks in the flow field, the method of steepest descent has been added to the calculation scheme. Results for subcritical and supercritical flows past aerofoils are given and compared with solutions obtained by finite-difference techniques.

The linear, second-order, ordinary differential equations governing the free-vibration characteristics, in vacuo, of discretised systems executing, at equilibrium, steady rotational motion about a fixed point may be expressed in the well-known matrix-vector form involving real symmetric and skew-symmetric coefficient matrices. Less well known is the fact that the corresponding Hamiltonian first-order system may be cast into a special form involving a skew-symmetric system matrix. In this paper the computational merits of this special form are exploited in the calculation of the natural frequencies and modes of the rotating system.

The results of measurements in laminar flow along a straight 135° corner are presented. Near to the inlet edge plane the flow has an appearance resembling that reported by Zamir and Young for a 90° corner in which the isovels in transverse planes are concave outwards near the bisecting line of the corner, but unlike the 90° corner flow this characteristic diminishes with distance downstream in the case examined here. The analytical solution by Carrier is found to be a good representation of the flow in the 135° corner.