For plane turbulent jets and wall jets in uniform streaming flow a simple method, based on a simple empirical formula for the rate of growth which differs from that proposed by Abramovich, is presented. The predictions of length scale, l0, and velocity scale, u0, are in good agreement with experimental results for all ratios of free-stream to jet exit velocity and the eddy viscosity Reynolds number has the correct asymptotic values.

To study the effects of flow non-uniformities on the hypersonic flow past test bodies, perturbation analysis is applied to the hypersonic source flow past wedges and cones. In both cases it is shown that the effects of the source flow on the shock shape and velocity are small, while effects on the pressure and density are large. Curves are presented for various values of the Mach number from which these effects can be estimated.

This paper presents the results of some calculations of the incompressible turbulent boundary layer on an infinite yawed wing. A discussion is made of the effects of increasing lift coefficient, and increasing Reynolds number, on the displacement thickness, and on the magnitude and direction of the skin friction. The effects of the state of the boundary layer (laminar or turbulent) along the attachment line are also considered.

A study is made to determine whether the behaviour of the boundary layer can adequately be predicted by a two-dimensional calculation. It is concluded that there is no simple way to do this (as is provided, in the laminar case, by the principle of independence). However, with some modification, a two-dimensional calculation can be made to give an acceptable numerical representation of the chordwise components of the flow.

This paper presents a theoretical analysis of the behaviour of thin-walled lipped channel beams subjected to end moments. In the analysis the beam section is assumed to be composed of a number of flat plates, joined at the edges. The mechanics of local instability of the walls of the beam are examined from a consideration of the strain energy stored in the component plates, and critical moments to cause local buckling are evaluated. The behaviour of the beam after local buckling is studied using a semi-energy method, whereby the stress and deflection systems throughout the section are linked by solving von Kármán’s compatibility equation for the component plates and the stress and deflection magnitudes are found from energy considerations. As collapse of the beam is approached, a simple plasticity analysis is incorporated in the theory in order to evaluate the collapse moment for the beam.

The results of the analysis are compared with the findings of an extensive experimental investigation and it is shown that the theory is very accurate in its prescription of the experimental stresses and deflections. Comparison of the theoretical and experimental collapse moments also verifies the validity of the theoretical analysis.

Earlier papers described a method of calculating three-dimensional turbulent boundary layers based on the use of momentum-integral equations in the streamwise and cross-flow directions. Here the method is applied to a problem which is initially formulated in a coordinate system appropriate to the somewhat complex body geometry. Transformation to a streamline coordinate system is then made before the application of a rapidly converging iterative method of solution. The calculations, which are confined to single Reynolds number and a particular value of the rotation parameter, show the very large increases in drag and torque that accompany early transition.

The impingement region produced by directing a uniform, axisymmetric, supersonic jet of air normally onto a large, flat plate has been investigated experimentally and theoretically for four jets in the Mach number range 1·64 to 2·77. A qualitative theoretical description of the flow in the neighbourhood of the sonic line is given. A single-strip version of the method of Polynomial Approximation and Integral Relations (PIR) is applied to the flow, using two alternative methods of determining the centre-line shock height. The PIR predictions are compared to experimental shock shapes and pressure distributions. It is found that a PIR method in which the sonic line is assumed to intersect the shock at the jet edge leads to very good agreement with experiment at the higher jet Mach numbers, but accuracy is much reduced at the lower Mach numbers, the shock height being in error by about 62 per cent at a jet Mach number of 1·64. A change in flow pattern at small nozzle-to-plate distances is reported.