Community Research and Development Information Service - CORDIS


ACCUBLADE — Result In Brief

Project ID: 338543
Funded under: FP7-JTI
Country: Spain

Smart systems into rotor blades come a step closer

Active systems in helicopter rotor blades can adapt the blade's aerodynamic properties, leading to lower fuel consumption, increased maximum speed and reduced noise. An EU project developed a highly accurate and low-cost moulding process for manufacturing composite rotorcraft model blades incorporating active systems, making future helicopters become smart.
Smart systems into rotor blades come a step closer
Of all the active rotor systems currently under development, the active gurney flap (AGF) has been selected in the Green Rotorcraft subprogramme of the Clean Sky Joint Technology Initiative. The AGF system lowers the tip-speed ratio of the blades, resulting in less noise and vibration and high-efficiency operation.

Validation of innovative AGF systems requires the manufacturing and testing of small-scaled model blades in wind tunnel tests before their implementation at full scale. The ACCUBLADE (Low cost design approach through simulations and manufacture of new mould concepts for very high tolerance composite components) project facilitated validation of technology into wind tunnels by designing moulds for the manufacturing of the model rotor blades that incorporate AGFs.

Efficient integration of the AGF system into small-scaled model blades with state-of-the-art prepreg technology is difficult to achieve. The ACCUBLADE project devised an efficient method for designing moulds based on process simulations, eliminating the need for expensive and time-consuming trial-and-error experimental procedures.

Researchers developed new thermal and impregnation models and used them for the analysis and optimisation of critical process-related issues. These included shape distortions caused by the different thermal expansion coefficients of the materials, temperature gradients or potential resin flow defects.

Results from laboratory tests on composite materials served as input data for the modelling of the most relevant causes of distortions, including warping and spring-in phenomena.

Simulation activities led to obtaining an optimised mould design for accurate processing of the model rotor blades. Researchers then manufactured highly precise moulds and polished the surface to become smooth. The technology allows obtaining net-shape rotor blades either by conventional moulding of prepregs or by another moulding method that combines prepreg processing and liquid moulding. In-mould sensors enabled efficient monitoring of the process parameters.

Results from inspection tests of the first model blades were promising.

ACCUBLADE developed a green route for mould manufacturing that reduces material waste and energy consumption, while also allowing faster implementation of innovative AGF systems into rotor blades.

Related information


Rotor blades, active systems, moulding, active gurney flap, ACCUBLADE
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