Realistic next-generation wing model for testing
Air travel continues to increase with increasing globalisation, bringing both people and cargo to distant destinations for pleasure and business. Fuel consumption high in the atmosphere releases emissions where they have the largest and most immediate effect on global climate. The European Clean Sky initiative is the EU's most ambitious aeronautical research programme ever. It is a unique public-private partnership to significantly decrease the environmental impact of flight, and the GRA is one of its platforms. The EU is funding the ETRIOLLA (Experimental transonic investigations on laminar flow and load alleviation) project to develop a realistic wind tunnel model to test a novel wing concept for the GRA. The wing is designed to facilitate natural laminar flow (NLF) that will reduce drag as well as for load control and alleviation (LC&A) to manage passive gusts of wind and reduce weight on the plane. Both will reduce fuel consumption and emissions. ETRIOLLA has faced and overcome important challenges to make the wing model as realistic as possible given the constraints of wind tunnel testing. The model is as large as possible to generate high Reynolds numbers (associated with turbulent flow) yet fit within the geometric confines of the wind tunnel. More than 40 global and partial structural models were assessed, resulting in selection of a wind tunnel candidate configuration. However, subsequent studies showed that a conventional wind tunnel model with full strength and stiffness could not fulfil requirements, bringing the team back to the drawing board. Scientists came up with an innovative solution that increases bending stiffness and reduces torsional stiffness. The team evaluated optimisation of two LC&A device settings and chose the one that increased performance under cruise conditions. All materials have been ordered and partners have begun the manufacturing process. Preliminary models for virtual testing preceding the actual wind tunnel testing have been developed. ETRIOLLA expects to answer important open questions about NLF and LC&A devices for the GRA wings. This will increase the EU's competitiveness in both the associated technologies and as airlines with minimal environmental impact in an increasingly eco-friendly consumer society.
Keywords
Wing model, Green Regional Aircraft, wind tunnel, transonic, laminar flow, load alleviation
