The challenges of helicopter simulation are being tackled across a broad front as technology is developed to meet the needs of Industry. Traditionally, the strongest impetus has come from the training community and this is likely to continue for some time as simulation technology advances at increasing pace, raising fidelity standards. The development of PC-based simulation technologies is providing a significant spur in this development and lowering the cost, making complete simulation systems of reasonably high fidelity available to smaller organisations. This paper describes the first year of operation with such a system at the University of Liverpool – HELIFLIGHT. With its full motion, wide field-of-view visuals, programmable force-feel system and the comprehensive FLIGHTLAB modelling environment, we describe the HELIFLIGHT system as high fidelity and the first year of utilisation saw extensive use in a variety of handling qualities and pilot-vehicle technology research and teaching. Some of these are described in the paper and from a year of many highlights, the EU-funded programme to develop handling qualities for a civil tilt rotor aircraft is selected to demonstrate the versatility of the HELIFLIGHT system.

This paper reviews the research on Gurney flaps and related high lift trailing edge devices. It investigates aerofoil performances at Reynolds numbers Re ≅ 105 and below, both with the clean configuration and various Gurney flap sizes. The device height is optimised, and a semi-empirical formula linking flap height to free stream speed and aerofoil chord is proposed. The analysis shows that the optimal size of the device is always below the boundary-layer thickness at the trailing edge. Discussion of results includes analysis of hysteresis loops occurring in the L/D performances. These are mostly due to large changes in drag and small changes in lift, which occur when the aerofoil is restored to the reference angle of attack.

Aeronautics faces new and increased challenges in the 21st century. These include climate change, long-term fuel supply, traffic congestion, and noise pollution. Radical technological steps will be demanded of the industry in order to maintain a sustainable transportation system.

In setting out its ideas for a Sonic Cruiser, Boeing has recently acknowledged that there is a need to look beyond the high-aspect-ratio wing with separate fuselage and podded engine configuration, which it pioneered at the start of the Jet era.

This paper sets out the case for the broad delta including its advantages as a basis for achieving higher transonic cruising speeds, with very long range and large payloads, while providing progressive and significantly improved environmental impact. The work is based on concept designs drawing on flight and weight data from the Vulcan bomber and the Concorde aircraft – both pioneering designs, by no means at the end of their technical potential.

A broad delta is taken to mean an aircraft of aspect ratio in the range 2 to 4. Not only does such a planform have application to many sizes of airliner, cruising at various high subsonic speeds, but also it is inherently well suited to later application of laminar flow. Wing surfaces undisturbed by flaps and slots and unhampered by very thick wing skins, together with favourable engine inlet locations, could be a basis for improved overall aerodynamic efficiency.

Airliners designed for operation in the region of Mach 1 are likely to pose more difficult problems for the aerodynamicist. Designs must cater for both cruise and maximum design speeds, which may encompass the Mach 1 condition.

A numerical study of drag reduction by mini-belts in a smooth wall turbulent boundary layer is carried using a second-moment closure turbulence model. The main objective of this exploratory work is to investigate the possibility of using mini-belts, driven by frictional drag only, to reduce the drag of a smooth wall. The results clearly show that such technique can be an effective and cheap means for achieving drag reduction. Furthermore, it is observed that, in contrast to riblets, the use of mini-belts does not suffer from geometrical or size constraints in the context of drag reduction. Also mini-belts will always reduce the skin friction regardless of the flow regime (laminar, transitional and turbulent). These advantages may quite well balance the major difficulty related to their mounting in practical situations

This paper outlines an initial investigation for determining nonlinear aerodynamics for unsteady transonic flows through the use of curve fitting unsteady computational fluid dynamics (CFD) data. The full aerodynamics including linear and non-linear aerodynamics can be identified as a polynomial function. Through the curve fitting method, the important non-linear terms can be identified and the smaller terms can be neglected. Having modelled the non-linear aerodynamics and included into the aeroelastic model, the characteristics and stability of non-linear aeroelastic system can then be investigated using normal form theory. The methodology is demonstrated upon a simple two-degrees-of-freedom aeroelastic wing model with structural and aerodynamics nonlinearity. A good agreement is obtained for all cases studied between analytical and simulation results.