An advanced design process applicable to thespecification of flight simulator cueing systems ispresented in this paper. This process is based onthe analysis of the pilot-vehicle control loop byusing a pilot model incorporating both visual andvestibular feedback, and the aircraft dynamics.After substituting the model for the simulatedaircraft, the analysis tools are used to adjust thewashout filter parameters with the goal of restoringpilot control behaviour. This process allows thespecification of the motion cueing algorithm. Then,based on flight files representative of theoperational flight envelope, the required motionsystem space is determined. The motion-base geometryis established based on practical limitations, aswell as criteria for the stability of the platformwith respect to singular conditions. With thisprocess the characteristics of the aircraft, thetasks to be simulated, and the missions themselvesare taken into account in defining the simulatormotion cueing system.

A numerical procedure, which utilises polynomial powerseries expansions for the optimisation of multipanelwing structures in idealised critical flutterconditions, is introduced and developed. It arisesfrom the Rayleigh-Ritz method and employes trialpolynomial describing functions both for theflexural displacement and for the thicknessvariation over the multipanel surface. An idealisedstructural plate model, according to the Kirchhoff’stheory, together with a linearised supersonicaerodynamic approach, are supposed. The classicalEuler-Lagrange optimality criterion, based onvariational principles, has been utilised for theoptimisation operations, where by imposing thestationary conditions of the Lagrangian functionalexpression, a nonlinear algebraic equations systemis obtained, whose solution is found by anappropriate algorithm. By utilising an iterativeprocess it is possible to reach the referencestructure critical conditions, with an optimisedthickness distribution throughout the multipanelsurface. The final part of the work consists insearching the minimum weight of the multipanelplanform wing structure with optimised thicknessprofile vs the flutter frequency,considered as a variable imput parameter, for fixedflutter speed and equal to the critical one of thereference uniform structure.

An investigation into the behaviour of clusteredsynthetic jet Actuators for flow-controlapplications is described. Experiments have beenundertaken with two small-scale synthetic jetactuators in a zero-pressure gradientboundary-layer, in order to investigate the effectof configuration yaw angle and relative input signalphase. Oil-flow visualisation and hotwire anemometrytechniques were used, demonstrating that changes inthe downstream flow structure could be observed.Compared to a streamwise configuration, in which asymmetrical counter-rotating vortex pair wasproduced by the synthetic jet-boundary-layerinteraction, a broader asymmetric interaction wasproduced in a 15° yaw configuration. Streamwisevelocity contour plots, illustrating the developmentof the interaction downstream, over four phaseangles, were presented. Significant differences inthe PSD analyses of downstream streamwise velocitytime histories were found, suggesting that inputsignal phase could influence the stability and henceeffectiveness of flow structures used inflow-control applications.

This article deals with a damage simulation of flightcontrol systems during a flight. As a subject offlight tests the model of a classic aerodynamicaircraft scheme is considered. This aircraft hashighly swept wings a moderate wing elongation andall-moving horizontal tail surfaces. The diagrams offlight parameters from flight tests of the freelyflying models with loss of a control surface inflight are given. The investigation results for thefailures leading to a sharp drop in the stiffness ofthe control units in the pitch channel are given.The damage investigation in horizontal flight and incomplex manoeuvres is given.

Vortex merger is studied within the context oftwo-dimensional discrete vortex sheets anddemonstrated on two equally oriented circularvortices and aircraft tip and flap vortices. It isconfirmed that, depending on the wing loaddistribution, the latter may or may not coalesceinto a single counter-rotating pair. The interactionof a vortex with an equally oriented shear layer,governed by the same physical principle, suggests apossible intensification of an aircraft vortex incross-wind shear.