FOR AUTO RTM

Fan Blade
High-Pressure
Compressor
Combustor
Low-Pressure Turbine
Spinner
Low-Pressure
Compressor
Aeroengine Composites,
Part 2: CFRPs expand
High-Pressure Turbine
CFRPs: Inward and rearward
A cross-section of GE Aviation’s (Cincinnati,
OH, US) GE90 turbofan engine, the first to
use CFRP fan blades in service. Today, the
use of CFRP is increasing from the cooler
front fan and outer applications toward the
hotter rear and inner sections. For CMCs, the
evolutionary growth paths are in the opposite
directions, forward, from hotter to cooler
zones and from inner to outer structures.
Source | GE Aviation (text added by CW}
Proven in fan blade/
case applications,
carbon fiber-reinforced
polymers migrate to
previously unanticipated
destinations nearer the
engine “hot zone.”
By Ginger Gardiner / Senior Editor
» Since 1980, average fuel usage in commercial aircraft has plummeted by
27% for widebody aircraft and 35% in narrowbody models. Composites have
played an indispensable role in that transformation. But as noted in the CW
August 2015 issue’s Market Outlook: “Aeroengine Composites, Part 1: The CMC
Invasion,” the Advisory Council for Aviation Research in Europe (ACARE) has
called for a 75% reduction in CO 2
per passenger-km, a 90% reduction in nitrous
oxide (NOx) emissions and a 65% reduction in noise by the year 2050 compared
to performance levels recorded in 2000 (see “Learn More,” p. 44). This is just
one of many programs aimed at demonstrating cleaner, quieter and higher
performing aircraft engines within the next few decades.
Part 1 chronicled the migration of ceramic matrix composites outward from
obvious applications in the aeroengine “hot zone,” where engine components
must handle high temperatures generated by combustible gases in the core at
the engine’s rear. In Part 2, we see carbon fiber-reinforced polymers (CFRP)
evolving inward and rearward from now familiar duty as replacements for
metal in fan blade and fan case to once unlikey duty nearer the hot zone.
Evolution of CFRP in turbofans
A key driver for composites use has been the need to increase the engine
bypass ratio (BPR). BPRs have increased from 5:1 in the 1970s to 10:1 for the
new LEAP engine and 15:1 for the Rolls-Royce (London, UK) UltraFan, aimed
40 SEPTEMBER 2015
CompositesWorld