Mechanical Analysis Of Trailing-Edge With Morphing Skin

The morphing aircraft can meet several mission requirements like altitude cruisingand fast attack etc. by changing the wing shape. It can improve flight performance andexpand flight envelope significantly. The variable-camber wing is an important researchfield in the study of morphing aircraft. The Variable-camber wing has been changedform traditional deflexion flap to the integration of adaptive skin or intelligent skin andnew deformation structure. The advantage is that the wing surface always maintainssmooth and continuous during morphing so that the flow separation can be put off. Inthe civilian areas, the variable-camber wing can increase the lift of the airplane andreduce the drag to improve the economy. Variable-camber wing has a huge prospectsand worth to be studied deeply.In this paper, a detailed study about the variable-camber wing is carried out withnumerical simulation. First of all, the variable-camber wing is studied by numericalsimulation to get its lift, drag, pitching moment and other parameters. Compared withtraditional wings, the variable-camber wing's aerodynamic characteristic is obtained.The results show that in the same condition, the variable-camber wing can bring greaterincremental lift and reduce the drag.In the study of morphing skin, static aeroelastic deformation of flexible skin underaerodynamic loads is analyzed. The characteristic of shape memory polymer skin isanalyzed also. The effect of bubbled deformation of flexible skin on the aerodynamiccharacteristics and the design parameters of skin were discussed. Numerical resultsshow that the flexible skin on the upper surface of trailing-edge will bubble underaerodynamic loads and the bubble has a powerful effect on the aerodynamiccharacteristics. The bubble can reduce the increment of lift coefficient and increase thedrag coefficient. With the increase of the attack-angle, the bubble gets smaller and theeffect gets weaker also. The shape memory polymer is a suitable choice for themorphing skin but the velocity is limited when shape memory polymer is in rubberstate.In this paper, a new flexible trailing-edge structure is designed. Static aeroelasticdeformation of flexible trailing-edge structure under aerodynamic loads is analyzed.Simulation results show that the trailing-edge deflection angle gets bigger with the dropof modulus under the same driving-force. But the middle of the flexible trailing-edgestructure can rise up under aerodynamic loads if the modulus is too low. This rising-updeformation will change the deflection track required and reduce the benefit caused bythe trailing-edge deflection.