Measurements of the turbulent boundary layer on a sidewall of the RAE 8 ft × 8 ft wind tunnel are described. Velocity profiles and wall shear-stress measurements were obtained for a Mach number of 0·8 over a Reynolds number range of over a decade up to a value of nearly 400 million.

A skin-friction relationship is deduced together with a description of the velocity profile and boundary-layer growth based upon the velocity-defect law using kinematic parameters for constant-pressure flows without heat transfer.

Previous data for Mach numbers up to 2·8 obtained in the same tunnel are shown to be well matched with the present analysis and the use of simple scaling factors for compressible flows is confirmed.

This paper describes a simple method for smooth curve fitting or function interpolation. Where possible, the method uses continuous piece-wise conies in preference to cubics so as to prevent the occurrence of extraneous inflection points. The method is ideal for single-valued functions with sharply changing gradients such as occur in pressure distributions, containing shock waves. A version that is valid for multivalued functions is also described.

A numerical method for calculating transonic flow around general inlet configurations is presented. The method is based on a finite volume potential flow algorithm with enhancements to reduce truncation errors. An approximate factorisation iterative scheme is employed and the computer code is written to take advantage of the architecture of a vector computer. The method has also been coupled with an integral boundary layer method to take into account viscous effects on the inlet surface. Results are presented for a number of configurations which are representative of current design trends, at both take-off and cruise conditions. Comparison with experimental data shows favourable agreement. The method is shown to be accurate, reliable and cheap to run.