An experimental investigation was carried out of the incompressible boundary layer flow along a flat plate, in the presence of an adverse pressure gradient that corresponds to a linear retardation of the free stream velocity. The turbulence level in the free-stream was 0·12% and transition occurred with the laminar boundary layer being close to separation. For three values of the Reynolds number (2·56, 3·11 and 4·09 million based on the reference length that is defined as the reciprocal of the nondimensional-velocity gradient) the laminar, transitional and turbulent regions were studied by single (normal) hot-wire surveys at several streamwise positions. This allows the fluctuations of the streamwise velocity component to be followed from the amplification of laminar instability waves, through breakdown in the intermittency region, and the subsequent development towards a more or less developed turbulence structure. The study reveals that within the transition region fluctuation levels are reached throughout a large part of the boundary layer that are significantly higher than those in fully developed turbulent flow, which is partly a direct consequence of the intermittent character of the flow. For the highest Reynolds number additional cross-wire surveys were carried out in the turbulent region to observe the development of the turbulent stresses following transition. The data are interpreted in terms of structural coefficients, eddy viscosity and mixing length. Also, these results indicate that the transition process can be associated with turbulence levels well in excess of those occurring in fully developed turbulence, and reveal the relaxation of the outer region turbulence structure.

This paper is meant primarily for non-specialist readers who may not be familiar with aeroelasticity. The main objective is to direct the reader to some important texts and papers that have been published in the areas which embrace aeroelasticity, from which the reader may gain sufficient knowledge about the subject. Since aeroelasticity is a large field which requires considerable knowledge in several related areas newcomers can often be daunted by the subject. This is further compounded by the great amount of published material available. This paper will assist the reader to locate key publications and help identify major works which have been useful in studying the subject. A comprehensive list of references is included which will help to identify key subject areas, researchers, research establishments and publications for further study.

Modelling the response of solid rocket motors to bullet and fragment impacts is a high priority among the military services from standpoints of both safety and mission effectiveness. Considerable effort is being devoted to characterising the bullet and fragment vulnerability of solid rocket motors, and to developing solid rocket motor case technologies for preventing or lessening the violent responses of rocket motors to these impact loadings. Because full-scale tests are costly, fast-running analytical methods are required to characterise the response of solid rocket motors to ballistic impact hazards. In this study, a theoretical first-principles-based model is developed to determine the partitioning of the kinetic energy of an impacting projectile among various solid rocket motor failure modes. Failure modes considered in the analyses include case perforation, case delamination, and fragmentation of the propellant simulant material. Energies involved in material fragmentation are calculated using a fragmentation scheme based on a procedure developed in a previous impact study utilising propellant simulant material. The model is found to be capable of predicting a variety of response characteristics for analogue solid rocket motors under high speed projectile impact that are consistent with observed response characteristics. Suggestions are made for improving the model and extending its applicability to a wider class of impact scenarios.

An experimental investigation of cone cavity flow at M = 8·2 with injection of air and helium has been performed in the Cranfield University gun tunnel. The cone used had a 10° semi-angle and incorporated an annular cavity. The boundary layer ahead of the cavity was laminar. The study concentrated on the effects of increasing the mass injected into the cavity.

With no injection the external flow bridged the cavity. A shock wave and a pressure peak occurred at the rear face corner. By injecting gas, this pressure peak was decreased in intensity and a shock wave was formed at the front face corner. As the mass injected was increased, the shocks initially formed at the front and rear face corners were shifted upstream from their initial positions and boundary layer separation occurred ahead of the cavity. For the highest mass flow rate injected, the pressure peak at the rear face corner was very small. The cavity flow was never more than mildly unsteady.

Numerical results are presented for two-dimensional vortex-aerofoil interaction using a grid-free discrete vortex method. The effects of the passing vortex on the surface pressure distribution and hence the aerodynamic force and moment of the aerofoil are examined in detail for a variety of interaction geometries. For some head-on interaction cases, vortex-induced local flow separation is also predicted on the aft part of the aerofoil surfaces. Extensive comparisons are made with other numerical results and the results from the Glasgow University BVI wind-tunnel test, which show good agreement.

The accurate prediction of ground effect aerodynamics is an important aspect of wing-in-ground effect vehicle (WIG) design. Computational fluid dynamics (CFD) solutions are useful alternatives to expensive (especially in the case of ground effect) wind-tunnel testing. However, the incorporation of the rigid surface effects often leads to confusion due to such a model being in a vehicle fixed reference frame (air moving, vehicle fixed) rather than the real-life situation of a ground fixed reference frame (air fixed, vehicle moving).