Experiments have been performed to study the influence of multiple surface static pressure tappings on transition of the boundary layer on a circular cylinder in cross-flow. A wide range of tapping and cylinder dimensions have been examined to demonstrate that the tappings can act in the same way as trip wires or other surface roughness to reduce the Reynolds number at which transition occurs. Hence, the pressure distribution around the cylinder may be influenced by the presence of the tappings, leading to incorrect measurements. Examination of the data has resulted in a correlation which should make it possible to avoid this tapping/boundary layer interaction in future experiments involving similar cylindrical bodies.

This paper is structured firstly to describe the operational requirements of a modern military aircraft with particular reference to its armament systems, secondly to derive and consider developing architectures for armament control and thirdly to present one of the architectures from an implementation point of view.

The paper concludes that the optimum architecture for safety, availability and control of airborne weapons can be derived logically from the military aircraft operational requirement. It is not necessary to indulge in over duplication to achieve a cost effective, safe and available system.

The aerodynamic energy method provides a means of flutter-suppression control-law design based wholly on oscillatory aerodynamic forces on a notional structure with notional normal vibration modes. The method has been proposed as a means of flutter suppression regardless of structural considerations, other than those mentioned. As originally conceived, the method is based upon the assumption of totally irreversible active controls. In this paper, the effects of finite impedance of actuators on the implementation of the method are investigated analytically. The conclusions do not augur well for the method.

The objective of this paper is a description of animal swimming and flying locomotion in terms of wave theory. In this context various oscillatory organs of locomotion, such as flagella, fins and wings, are interpreted as waveguides capable of transmitting mechanical transverse waves. Furthermore, the Poynting concept is used, according to which every type of wave transports not only energy but also momentum. Even with no detailed knowledge of the hydro- and aerodynamic flow fields it is possible to calculate the wave power, the propulsive force, and the propulsive efficiency with the means and methods of vibrational theory alone.