Recent advances in aeronautical technology are reviewed, with particular reference to work in the United Kingdom, and the process is outlined whereby these have progressed from fundamental research through to exploitation in marketable products. Aerodynamic, materials, propulsion and avionic aspects are discussed and successful applications described in commercial and combat aircraft and helicopters. Current and anticipated advances in technology are considered in the context of possible future applications, including brief consideration of the possibility of a new generation of supersonic transport aircraft. Lessons are drawn from past experience on actions necessary now if these advances are to be exploited successfully in improving the performance, or reducing the acquisition or operating cost, of the next generation of aircraft, without introducing an unacceptable level of risk.

The results of a blade-vortex interaction (BVI) study incorporating particle image velocimetry (PIV) are presented. Test cases encompass a variety of intersection geometries, including head-on parallel interactions. Results provide quantified flow visualisation images of the flows generated near the blade tip and inboard during interactions. PIV results are examined in the light of understanding gained from previous pressure measurements made from the same BVI facility. Both the difficulties and the advantages of utilising the PIV technique in this application are discussed.

Effective control of combat aircraft at high angles of attack requires the flight control system to operate to higher frequencies and gains. This increases the possibility of excitation of the structural modes by altering the aeroservoelastic stability of the complete system. This paper details the results of tests carried out on a rigid, 55° leading edge sweep delta wing, half model fitted with a half span elevon operated through a closed loop control system. The effects of steady elevon deflections up to 40° angle of attack are described. The unsteady pressures resulting from elevon oscillations at frequency parameters up to a value equivalent to the first wing bending mode of a typical combat aircraft have been measured. The effect of the elevon oscillation on the elevon itself and on the bending mode have been estimated by calculating the unsteady hinge and root bending moments about the wing root. The lower surface, unsteady elevon effects were found to be independent of incidence and frequency parameter. The amplitude of response of the weak vortex on the upper surface of the wing reduced rapidly with frequency parameter. Above an incidence of 10°, the vortex breakdown was above the wing and led to a further reduction in the vortex response. The vortex response lagged the elevon motion.

A number of modern “aerodynamic” bicycle wheels were tested at full scale speeds in a windtunnel. The effects of wheel geometry, rotational speed and cross winds on drag force, side force and yawing moment were investigated.

Compared with a conventional spoked wheel, all the “aerodynamic” wheels were found to give similar improvements in drag of approximately 25%. In cross wind conditions, aerodynamic characteristics were strongly dependent on wheel geometry, but essentially independent of wheel rotational speed.