Unsteady spiked body flows were simulated by a second order time-accurate CFD method. Laminar, axisymmetric flow was considered at Mach 2.21 and Mach 6 freestreams and Reynolds’ numbers based on the blunt body diameter of 0.12 million and 0.13 million, respectively. A spiked forward facing cylinder with spike lengths between LID = 1.00 and LID = 2.40 was used as the model geometry. Following the numerical method’s verification, the individual flow modes of oscillation and pulsation were examined. The frequency of the events was found in good agreement with the experiment, while the pressure amplitudes were overpredicted in the Mach 6 cases. Analysis of the numerical results showed that the oscillation flow mode was driven by a viscous mechanism, whereas the pulsation by an inviscid one. The hysteresis phenomenon in the transition between the two flow modes was predicted qualitatively.

The interaction between slender body vortices and a single vertical fin located down the axis of the body is investigated numerically for angle of attack of 30 deg and Reynolds number of 6000. The present research includes a parametric study on the effect of fin location and fin azimuthal position. A numerical method based on the pseudo-compressibility is used for solving the three-dimensional incompressible Navier-Stokes equations using the Lower-Upper Symmetric Gauss-Seidel implicit scheme. The numerical results show that the vortices remain very coherent and attached to the body until they reach the fin section, where they become less coherent and begin to separate from the body. Also, the results show that the fin location does not affect the upstream development of the vortices, but it does affect the location at which the vortices separate from the body. The effect of azimuthal fin positions was also investigated. As the azimuthal angle of the fin increased, the size of the vortex on the port side decreased, but the starboard side vortex grew in size and moved across the leeward ray to the port side. The computed results are found to agree well with the available experimental data. The effect of the grid size on the numerical solutions was also investigated.

The influence of trailing-edge devices such as Gurney flaps and divergent trailing edges of different height on the aerodynamic performance of an aerofoil at transonic speeds has been investigated experimentally. The investigation has been carried out in the Transonic Wind Tunnel Göttingen (TWG) using the two-dimensional aerofoil model VC-Opt at freestream Mach numbers of M ε [0.755, 0.775, 0.790] and a Reynolds number of Re = 5.0 x 106.

The results have shown that the trailing-edge devices increase the circulation of the aerofoil leading to a lift enhancement and pitching-moment decrease as well as an increase in minimum drag compared to the baseline configuration. The maximum lift-to-drag ratio is considerably improved and the onset of trailing-edge flow separation is shifted to higher lift. Besides the increased rear-loading, a downstream displacement of the shock provides the main lift enhancement in transonic flow.

The simple Gurney flap provides the largest additional circulation of all geometries tested. The smoother turning of the flow due to the additional ramp of the divergent trailing edge leads to a smaller increase of circulation. Slightly less lift but considerably less viscous (pressure) drag is generated enhancing the maximum lift-to-drag ratio compared to the Gurney flap. The negative affect of the Gurney flap on the pitching moment is also reduced.

For the high divergent trailing edges, different ramp slopes have a significant influence on the aerodynamic performance whereas at low device heights the influence is considerably diminished.

The results show that the divergent trailing edge proves to be the better trailing-edge device at transonic speeds. The application as an element for an adaptive wing is generally possible.

Customers demand reliable products and such demands are reflected in the product specification and requirements documents. Indeed, contractual obligations are being introduced to ensure that the supplier meets the cost of unreliability. Thus, equipment suppliers must design products to perform reliably for the required product life. Moreover suppliers must provide sufficient evidence that their product will meet reliability requirements. This evidence is termed the reliability case. The main instigator for the use of the reliability case is the British Ministry of Defence (MoD) under the guise of Defence Standard 00-42 Part 3 but the concept is also becoming accepted in the commercial field as one of the key criteria for selecting products.

This paper describes the work carried out under a collaborative project funded by the UK Department of Trade and Industry (CARAD) entitled reliability enhancement methodology and modelling (REMM). More specifically it will concentrate on demonstrating the methodology in the form of providing the necessary guidance for building a reliability case. It will also discuss the challenges associated with design for reliability and demonstrate how the REMM tool will encourage designers to consider what might go wrong.

The REMM tool encompasses a reliability assessment model and this paper will describe and discuss the advantages of this Bayesian model with particular reference to decision making aspects during the design stage of a project.

Integrated engine management (IEM) is a technique for unifying and improving the control and health monitoring of gas turbine aeroengines by increasing the quality and quantity of information available about the engine's health and performance. The core of the system is a real-time engine simulation whose outputs are compared continuously with those of the real engine. Any differences between the predicted and measured outputs are attributed to inaccuracy in the simulation's component performance parameters (such as the compressor efficiencies) which are continuously trimmed to make the outputs of the simulation track those of the real engine. The result is a real-time simulation whose input-output behaviour matches that of the real engine very closely.

Air traffic management (ATM) for commercial traffic will need to meet major challenges in the coming years. The industry is faced with many questions, for example:

• What ATM system can we realistically expect to have in 2010, 2020 and beyond?

• What safety improvements should we target for?

• What business analyses are needed to drive innovation forward?

• What are the key questions to be answered about the balance of responsibility between air and ground?

• How do we best address ‘gate-to-gate’ ATM issues?

• What are the systems architecture problems?