Clean Sky: the Future of the Aviation Industry –Developments at Israel Aerospace Industries

摘要

The aviation industry is taking part in a collective effort to reduce thernenvironmental impact of aircrafts, especially due to forecasts which predictrnthat aircraft fleets will at least double in the next 20 years. Very ambitiousrngoals have been set in this area by the Advisory Council for AeronauticsrnResearch in Europe (ACARE), which established the "Clean Sky" JointrnTechnology Initiative (JTI) under the European Union's seventh researchrnframework program, aiming at improving the environmental footprint ofrnaeronautics. It is one of the largest European research project everrnlaunched, grouping together all European aviation stakeholders. . It wasrnlaunched in 2008 as a unique Public-Private Partnership between thernEuropean Commission and the industry, and during seven years it willrndevelop and demonstrate new technologies to mitigate the CO_2, NO_X andrnnoise impacts. .rnWithin the framework of "Clean Sky", the Eco-Design ITD-airframernplatform (Integrated Technology Demonstration-EDA), is directly focusedrnon the last ACARE goal:"To make substantial progress in reducing thernenvironmental impact of the manufacture, maintenance and disposal ofrnaircraft and related products". It addresses the selection, development andrndemonstration of promising materials and technologies having thernpotential to reduce weight, energy consumption, quantities of rawrnmaterials, emission of noxious effluents as well as the elimination ofrntargeted hazardous materials and the application of future regulations.rnThe new technologies will be matured to TRL 5-6 (TRL-TechnologyrnReadiness Level) through on-ground demonstrations. A significant part ofrnthe development is performed by external partners selected through Callsrnfor Proposals (CfP's) launched during the project by the participatingrncompanies with extra funding from the "Clean Sky' project. .rnIsrael Aircraft Industries (IAI) is one of the associate partners of the EDArnplatform and an important contributor in diverse fields of concern:rnmaterials and technologies, metals and composites and greening thernsurface treatments. Three demonstrators representing business jetsrnconfigurations, novel materials and technologies were proposed and led byrnIAI. The 1st demonstrator is a "Low weight green Metallic Fuselagernsection". Al-Li alloys such as 2198, 2050 and 2099 were evaluated asrnsubstitutes to currently used Al alloys such as 2024, 7050 and 7075.rnManufacturability was demonstrated and a stress analysis study showedrnthat at least 9% weight reduction could be obtained. Green manufacturingrntechnologies were developed for the novel Al-Li alloys: Chemical milling rnprocess was replaced by non-chemical dry mechanical machining andrnstandard machining by an MQL (Minimum Quantity Lubrication)rntechnology. Current surface treatments containing hazardous chromatesrnwere replaced by Cr free primer and a Sol-gel non-chromate chemicalrnconversion coating. Door hinges were manufactured by EBM (ElectronrnBeam Melting) technology to receive 52% weight reduction and requiredrnmechanical characteristics. The second demonstrator is a "Stiffened panelrncomponent for a wing application, using LCM (Liquid CompositernMoulding)". Two manufacturing concepts were developed; the 1st isrncomposed from stringers made of cured prepregs, co-bonded to the skin byrnan infusion process. The 2nd is composed of a complete preform structurern(developed through a CfP) to be infused by one shot. The two panels willrnundergo a full scale mechanical testing with the aid of another CfP. The 3rdrndemonstrator is a "Shelf Removal Assembly", part of the center radio rackrnarea. A new Magnesium WE43 alloy with good corrosion, ignitionrnresistance and excellent strength to weight ratio was selected to replace andrnimprove this part, which is currently manufactured from 2024 Al alloy andrncoated with traditional chromate coatings. With the assistance of a CfP,rnnew Magnesium sheet forming technologies for this alloy were developedrnand a removable shelf was manufactured with an actual weight reductionrnof 20%. Several non chromated coatings were tested and evaluated forrncorrosion protection on Mg and showed compliance to specificationrnrequirements. A non chromated selective conductive coating forrnapplication on the "Removable Shelf" is developed through a running CfPrnand shows promising results. .rnThe three demonstrators will be manufactured and evaluated in 2014-2015.