The UK OST Technology Foresight for defence and aerospace identified multi-sensor data fusion as a future critical enabling technology for the UK, requiring a coordinated research agenda. This review paper provides an overview of past research and applications of data fusion. The process of data fusion and sensor integration is formally introduced together with a variety of implementation architectures, that recognise data fusion as a critical element in overall systems integration. The various benefits and attributes of data fusion are discussed together with a brief review of potentially fruitful areas of future research.

Hingeless and bearingless rotor designs are today well accepted for modern helicopters. Continued development, however, revealed some deficiencies in the area of aeromechanical stability and vibration. In general there is a good basic understanding of how to avoid these instabilities. But since it becomes more and more desirable to focus rotor design on aerodynamic features and flight performance, these aeromechanical instabilities gain new importance due to the difficulties to provide the required damping.

Since all rotor concepts suffer from the lack of sufficient natural lead-lag or inplane damping most designs in use show artificial lead-lag dampers to overcome aeromechanical instabilities. Additionally, active control offers the possibility for an artificial stabilisation of aeromechanical instabilities. Meanwhile, many research activities focus on active control to augment rotor lead-lag damping and many authors demonstrate the potential inherent in this approach.

Inverse dynamics is investigated as an efficient means of generating large angle satellite attitude slew manoeuvres. The required slew manoeuvres are specified using high order polynomials which result in a smooth control torque profile. Such smooth torque profiles are of importance in avoiding excitation of elastic modes of the satellite structure. In addition, the polynomial functions may be used to define a slew trajectory between arbitrary initial and final states allowing track-to-track manoeuvres. To compensate for uncertainties in the satellite dynamics, the inverse control is extended to include feedback linearisation about the nominal reference trajectory. It is shown that for rest-to-rest slew manoeuvres the resulting composite control is robust to uncertainties in the satellite inertia matrix and to actuator degradation. In addition, it is shown that complex paths may be generated through the use of high order polynomial functions which contain all the information required to enforce user defined constraints and boundary conditions in a compact, computationally efficient form.

The flowfield characteristics of jets from plain and rectangular orifices with semi-circular cut-outs have been experimentally investigated for both sonic and underexpanded conditions. Detailed pitot pressure measurements revealed that the cut-outs had a strong influence on the emerging flowfield. The rectangular orifice with cut-outs at the minor axis ends showed more effective mixing with shorter core lengths and faster near field jet decay when compared with the plain rectangular and the rectangular orifice with cut-outs at the major axis ends. The general trend of variation of shock cell length with fully expanded Mach number was consistent with Tam's theory, but the shock cell length of orifice jets were less than that predicted by Tam.

This paper describes a detailed experimental investigation of turbulent heat transfer in a radially rotating tube with particular reference to its application to the design of cooled turbine rotor blades. The paper focuses on the strategy adopted, the description of the apparatus used, the method of data processing and a selection of measurements which illustrate the manner by which Coriolis force and centripetal buoyancy force interactively affect the local heat transfer along the leading and trailing edges of the tube.

As well as re-confirming the fact that Coriolis force and centripetal buoyancy have a significant influence on the forced convection mechanism present due to the through flow, a number of new experimentally-based observations are presented. An empirical correlation, which is physically consistent, has been developed which permits the interactive effect of Coriolis force and centripetal buoyancy on forced convection to be evaluated and quantified.

The work has been motivated by the need to understand the general effect of rotation on the performance of the internal cooling airways used in gas turbine rotor blades.

Many situations arise in which aerospace structures are subjected to high frequency excitation, in the sense that the wavelength of the induced dynamic response is much shorter than the overall dimensions of the structure. The application of the conventional finite element method to this type of problem faces two difficulties: (i) the short wavelength of the structural deformation requires the use of many elements, which renders the method computationally expensive or even impracticable, and (ii) the response of the structure at high frequencies can be very sensitive to structural detail, and thus response predictions for an ‘ideal’ structure may differ significantly from the performance of the actual system. For a number of years research effort has been directed towards the development of alternative analysis methods for high frequency vibrations, and recent developments in this area are reviewed in the present paper. The methods considered are: (i) hierarchical versions of the finite element method, (ii) the dynamic stiffness method, (iii)periodic structure theory, (iv)statistical energy analysis and (v) wave intensity analysis.