The SMARTERSHIELD project contributed to eliminate the hazards associated with the existence of ice on a lifting or stabilising surface. The ice accretion increases the aircraft weight, which combined with the reduction of lift, can imply an important increase of the necessary energy to lift the aircraft. SMARTERSHIELD will consider all the possible innovative technologies and concepts that could be useful to accomplish a high efficient new smart erosion shield.
Once the ice accretion is produced, the ice morphology can be determined by analysing its crystalline structure by means of a microscope and by determining its thickness (e.g. by calculating the increasing of weight). The de-icing capacity of the SMARTERSHIELD system was experimentally evaluated by using testing machines or by actuating the system if it is self actuated, all this in a thermal and hygroscopic controlled environment to properly reproduce realistic icing conditions during the test. To maximise the deformation of the leading edge metallic skin (also named "erosion shield"), SMARTERSHIELD minimised the efforts generated by the mechanical actuators, and provide at the same time capabilities to control the geometry of the deformations, it investigated from actuator technologies and materials through structural and material design, using engineering tools such as e.g. Finite Element Analysis.
Ice accumulation on aircrafts' wings generates severe problems in the vehicle performance mainly due to the combination of weight increase and lift reduction which in turn implies an increase on the energy consumption. This problem is faced nowadays by methods that vary from energetically evaporative anti-ice systems (prevention) to de-icing systems (corrective). The use of evaporative anti-ice systems is hampered nowadays due to the design of new fuel-efficient engines that limit the available amount of bleed air. As a result, more electric aircrafts using large generators to replace bleed air as an energy source have been developed. However, the amount of power that permits a full evaporative anti-icing electrically powered system is still out-of-availability of the current generators. In addition, in the green electric rotorcrafts no bleed air will be available, and therefore electric systems will have to be used. Therefore, spending research efforts in electrically efficient de-icing systems seems to be a good alternative. As regards the known de-icing systems, they are mainly divided into electro-thermal (thermal-based de-icers) and electro-mechanical (deformations-based de-icers) systems While the electro-thermal systems present several disadvantages in terms power needs and secondary effects in the de-icing process among others, the electro-mechanical systems are very well valued for their low power needs (in fact that they are "single points" actuators) and more important, they are non-intrusive to flow. In order to develop more efficient electro-mechanical de-icing systems, innovative technologies and concepts have to be investigated.
The SMARTERSHIELD project has contributed to this investigation by implementing a highly efficient new smart erosion shield. In order to do so, the following main objectives have been undertaken:
- To investigate propose and review technical concepts and technologies and determine the best design concepts.
- To find the key parameters and elementary design structure patterns.
- To maximize the deformations with minimum energy and provide a high control capacity of the deformations.
- To determine the best design concept.
- To evolve the best design concept to achieve a highly optimized detail design of a erosion shield prototype.
- Validate the proposed new design concepts and the prototypes design by means of FEA simulations and the necessary correlation process.
- To manufacture and assembly erosion shield mock-ups.
- To manufacture and assembly the testing bench for the mock-ups.
- To test and validate the mock-ups.
- To manufacture and assembly the erosion shield prototype.
- To manufacture and assembly the testing bench for the prototype.
- To test and validate the erosion shield prototype.
As a summary, the de-icing SMARTSHIELD system has been designed by means of engineering tools such as FEA and prototype design and validated by full-scale experimental tests. In order to maximize the deformations and its control and at the same time minimise the energy spent in the de-icing process, an investigation on the actuator technologies and materials design has been proposed as well.