In this paper we describe a new 35GHz air-borne radar developed jointly by DERA and Alenia Marconi Systems. This radar is a functional prototype of a more highly configured imaging radar which is designed to meet the needs for all-weather imaging both for future unmanned air vehicles (UAV) and for seekers in the next generation of surface attack weapons.

The radar achieves high range resolution through a combination of pseudo-random phase coding and frequency agility. This is then augmented by synthetic aperture techniques to allow forward looking high resolution 2D imagery to be obtained. The radar has been installed on a fixed wing aircraft and has been used to gather fixed and relocatable target signature data under tactically representative conditions.

The paper begins with a discussion of the requirements for such a radar and then a review of its design and performance is presented. This is followed by examples of target signatures gathered during the initial system flights and a discussion on their exploitation for surveillance, target acquisition and tracking.

Ion thrusters are well suited for near-Earth and deep space missions because of their exceptionally high specific impulse. Those already flying are also proving to be very reliable. The flow of neutral and charged particles within the different components of these devices is very complex and although they have been studied for several years, little of the detail of their internal operation is properly understood. Numerical simulations of these flows can potentially yield an improved understanding of the physical phenomena involved and in turn this should assist in the optimising of new designs and in achieving higher specific impulses. The external plume, which can potentially cause damage to other spacecraft components such as solar panels, has been the object of some studies but the flow within the internal chambers where many complex phenomena are suspected to occur has been seriously neglected. For this reason the present fully kinetic neutral and charged particle simulations, which take account of the ionisation processes and the applied magnetic field, have been conducted. The studies have been made on one specific electrostatic ion thruster - the T5 model produced by the Space Department at the Defence and Evaluation Research Agency (DERA, Farnborough, UK). Two regions within the thruster have been concentrated on, namely the exit area of the hollow cathode and the main chamber.

Basic requirements for aero engine parts are to carry loads at high temperatures safely over service periods of 30-40 years. This generally calls for the best and latest materials and for highly sophisticated design and manufacturing procedures.

These requirements are frequently in contrast to the desire to keep costs at affordable levels. This aims at the costs at both the customer’s side as well as the manufacturer’s side. The measures to reduce cost in the design and production phase are various:

• redesign to allow for less complex manufacturing processes

• reassessment of quality characteristics without reduction of overall quality (only those characteristics to be maintained which are really critical)

• acceptance of minor damage in new parts which would be acceptable for repaired parts according to technical standards

• assessment of all steps in the production process with respect to their influence on the final product properties

• more stabilised manufacturing processes which use only a portion of accepted tolerance bands to reduce the subsequent test effort

• change of material.

In the service phase, cost reduction can be achieved by optimum exploitation of part’s life potential. The means are improvement of the lifing concepts where portions of the crack propagation life may be utilised in addition to the traditionally cleared crack initiation life. Accurate records of life consumption can be obtained with modern systems for life usage monitoring.

Under the national research project, dubbed Turbotech II, in which MTU Aero Engines, DLR Institute of Propulsion Technology and EADS Corporate Research Centre participate, active noise control (ANC) has been tested with a scale model fan of one metre diameter for a high bypass ratio aeroengine. MTU’s task in this project was to develop a computer code to predict the sound field in the intake duct of the fan-rig by the use of active control. The primary objective of the numerical study was to specify numbers of actuators (loudspeakers) and error sensors (microphones) and their positioning to control the harmonic sound power, radiated upstream to the duct intake. The computer model is based on the geometry of an annular or circular duct of rigid walls and infinite length, containing a subsonic axial uniform flow. The modal amplitudes of the primary sound field are input data. The actuators are modelled by acoustic monopoles. Two control algorithms have been used for achieving the control objective. The first consists simply in the reduction of the in-duct mean squared pressures. The second, so called modal control, is designed to cancel dominant modes selectively. Numerical results are presented using a typical configuration of wall mounted actuators and error sensors in the form of a number of rings uniformly distributed along the length of the intake duct. Guidelines have also been derived to design a favourable configuration of actuators and sensors. The findings of the numerical study are compared with the results of the ANC tests.

From Lanchester to the A380; from the era of the great pioneers to the integrated engineering teams and sophisticated analyses required to develop todays airliner. The ‘art’ of Aerodynamics has progressed a long, long way in the intervening century, but even with todays computational power it is still relevant to understand the basics and the early theories as developed by Lanchester and his contemporaries. In this lecture, the relevance of some of that early work and the compromises that must be made in optimising a modern wing design will be presented. These will include optimisation of spanwise loading, including trimming effects and winglets, and high and low speed aerodynamic and structural interactions, with examples drawn from the author's career in helping to develop the wings for the HS146 (now the RJX) and the Airbus family.

With the exponentially increasing computer power available over the last 30 years, the ‘art of compromise’ has progressively become the ‘science of optimisation’ and the lecture closes with a brief reference to techniques used to optimise current wing designs for the Airbus family.

An overview of some of the problems, which have to be overcome in the design of hypersonic missiles or projectiles, is given. In the main, these are connected with the high levels of heat transfer rate suffered by such vehicles, particularly those induced by aerodynamic control surfaces. Some of the aspects of heat transfer, induced by, and suffered by such controls are presented. Data are presented and discussed, regarding the effects of flow separation due to flaps or flares, the effects of sharp and bluff fins (both swept and unswept). Finally, the aerodynamic interactions and heat transfer rates induced by reaction control jets are presented.