The chairman: I know that everyone here shares with me our pleasure in welcoming as our lecturer one of the most distinguished and one of the most erudite and delightful people of all those who over the years have made their mark on British aeronautics. Lord Kings Norton has been Chancellor of Cranfield Institute of Technology since 1969. He began his career in aviation sixty-one years ago at Cardington, as a young engineer working on the design and construction of that much maligned major project, the airship R101, and then subsequently as Dr. Harold Roxbee Cox (as many of us still remember him) he was the head of the Air Defence Department of the Royal Aircraft Establishment at Farnborough. Next he was Chief Technical Officer of the newly formed Air Registration Board before he returned to the RAE in 1939 as Superintendent of Scientific Research.

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.

Whittle is one of the great engineers of the century, perhaps the greatest if judged by the scale of the consequences of his invention. Only the discoverer of the properties of the silicon chip could claim comparable importance.

Jet propulsion was first demonstrated by Hero of Alexandria in AD 60. The gas turbine was patented by Barber of Nuneaton in 1791. Whittle patented a design for an aircraft engine in 1930 in which propulsion was to be achieved by a jet produced by a gas turbine. By combining the thoughts of two men separated in time by over 1,700 years he made an engine which revolutionised world air transport.

Motivated by a lack of sufficient local and national computing facilities for computational fluid dynamics simulations, the Affordable Systems Computing Unit (ASCU) was established to investigate low cost alternatives. The options considered have all involved cluster computing, a term which refers to the grouping of a number of components into a managed system capable of running both serial and parallel applications. The present work aims to demonstrate the utility of commodity processors for dedicated batch processing. The performance of the cluster has proved to be extremely cost effective, enabling large three dimensional flow simulations on a computer costing less than £25k sterling at current market prices. The experience gained on this system in terms of single node performance, message passing and parallel performance will be discussed. In particular, comparisons with the performance of other systems will be made. Several medium-large scale CFD simulations performed using the new cluster will be presented to demonstrate the potential of commodity processor based parallel computers for aerodynamic simulation.