A cooling system for SMA (Shape Memory Alloy) based on the use of peltier cells

Recently the development of new aeronautical structures and the implementation of innovative materials has been mandatory for succeeding in critical tasks in terms of weight, fuel consumption, aerodynamic efficiency, cost reduction and so on. In fact, improvements in terms of aeroelastic behaviour, stability and manoeuvrability performance have been proved in the past, but now a new aircraft design concept is necessary and Shape Memory Alloy (S.M.A.) materials are taken into account for more and more aerospace applications. S.M.A., are well doing for themselves for several engineering fields: from aeronautics to civils, from surgery to electronics and so on. Morphing wing field is benefiting of S.M.A.: some airfoil geometrical features (f.i. camber, chord) and some wing characteristics (twist angle, swept) are object of investigations aiming at producing suitable geometry variations achieving optimal configurations for different flight regimes. In this work a S.M.A. tape, used as actuator system for a flap deflection by activation and de-activation through heating and cooling, by assuming complete Austenite and Martensite concentration, as initial and final states, has been considered. In particular drawback of S.M.A. is the activation ??? deactivation time: even if the activation phase of S.M.A. tape, by heating through Joule effect, is reasonably fast, the de-activation phase by cooling the system is actually an open problem for this type of materials. According to a real flap deflection on a civil aircraft actuation time has to be very fast in order to allow all manoeuvres during the flight. In this PhD thesis a new concept of cooling time reduction of S.M.A. de-activation has been dealt with by means of a Peltier cell bonded on the S.M.A tape. This is an innovative solution in terms of energy reduction because it is possible to shunt current from the system in order to supply the Peltier cell for the cooling effect on the tape. The intent of the international scientific community is related to the reduction of energy consumption for the civil aviation in general and the adaptive wing is a choice as provided by a lot of theoretical and experimental studies. In order to assure improved performance in different flight regimes actuator. Finally a correlation between numerical and experimental results have been presented demonstrating the validity of the obtained results through the developed investigations. This sytem, composed of Peltier cell has confirmed also an energy consumption reduction because the cell has been used for heating and cooling phase without additional system as resistive system (Joule effect). This project shall be also industrial involvement in a new cost cut down point of view.