GOLD Blade Dynamics BD 78 Blade
Only months before US giant GE bought Blade Dynamics, the UK-based company completed manufacture of a 78-metre prototype blade weighing only around 22.5 tonnes.
Its modular lightweight design and automotive-type manufacturing methods for enhanced product quality permit relatively simple tooling and an uncomplicated low-cost factory set-up. Additional benefits include flexibility in manufacturing locations close to markets, or even large wind projects, potentially revolutionising rotor blade supply chains.
The D78 blade incorporates a central load-carrying lightweight spar box composed of multiple carbon layers. Because the spar box assembly carries the main structural loads, the outer shell elements, built predominantly in glass-fibre reinforced composite, serve mainly as aerodynamic cladding, although they also contribute to the blade's structural integrity.
The blade consist of four sections with individual lengths of 30, 25, 10 and 13 metres starting from the blade root. The root section is composed of five "semi-flat" 72-degree segments, each incorporating Blade Dynamic's lightweight blade root design. The tip section has an in-house developed "BladeShield" anti-erosion layer fused within the component along the leading edge.
The intermediate blade section is flexible in length, enabling the manufacture of customised rotor diameters using similar mould tools and assembly facilities. This in turn allows a fast and flexible response to market demand, reducing the time-to-market for new blade variants.