A new methodology is described to identify aircraft dynamics and extract the corresponding aerodynamic coefficients. The proposed approach makes use of fuzzy modelling for the identification process where input/output data are first classified by means of the concept of fuzzy clustering and then the linguistic rules are extracted from the fuzzy clusters. The fuzzy rule-based models are in the form of affine Takagi-Sugeno models, that are able to approximate a large class of nonlinear systems. A comparative study is performed with existing techniques based on the employment of neural networks, showing interesting advantages of the proposed methodology both for the physical insight of the identified model and the simplicity to obtain accurate results with fewer parameters to be properly tuned.

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.

The practice of using mathematical models to simulate pilot behaviour in one–axis stabilisation tasks is a well–known conventional simulation problem. In this paper an accepted mathematical model of a pilot is used as the controller of a rudimentary helicopter model. Flight test manoeuvre data from inverse simulation runs is used to provide time–histories which represent input forcing functions to the pilot–helicopter system, and a constrained optimisation routine is utilised to obtain values for the pilot gain and lead/lag equalisation parameters. It will be shown that as the theoretical pilot is required to ‘fly’ different manoeuvres, or indeed if the level of manoeuvre aggression is varied, the ‘pilot’ adjusts these parameters to perform a tracking task in compensatory control. The paper considers initially the pilot and helicopter models and subsequently analyses the whole system, illustrating how the pilot model changes with different situations.

Numerical and experimental results are presented demonstrating the sensitivity of the performance of air-jet vortex generators (AJVGs) operating at jet to freestream velocity ratios of up to 4 to jet pitch and jet skew. The merits of installing co- or counter-rotational systems are shown. Numerical results for AJVG arrays on a flat plate in a zero pressure gradient indicate optimum values for jet spacing and velocity ratios to enhance the downstream skin friction above the uncontrolled value. The installation of a co-rotating array of AJVGs into a modified NACA 23012 unswept wing and the improvements in the lift and drag performance are illustrated. It is demonstrated that by careful implementation of boundary conditions in relatively straightforward ‘numerical’ experiments it is possible to carry out a sensitivity analysis on the vortex generator arrays before they are implemented in successfully enhancing wing performance.