Boeing puts ceramic matrix composites engine nozzle through its paces

Boeing has successfully flight tested the world's largest oxide ceramic matrix composite (CMC) structure — an engine nozzle designed to withstand high heat and help reduce engine noise.

Video: Boeing report on testing of oxide CMC engine nozzle.

Boeing reported on Sept. 5 that it successfully flight tested an innovative engine nozzle made of ceramic matrix composites designed to reduce noise, weight and lower fuel use. The ceramic matrix composite (CMC) nozzle went through a series of tests on the ecoDemonstrator 787 Flight Test Airplane, including community noise testing, passing over a large acoustic array in Moses Lake, Wash., USA.

Boeing engineers have been working on the technology over the last five years, so seeing all their hard work come to fruition is a great accomplishment, says Mitch Petervary, the technology’s principal investigator.

“This program began years ago with small samples in labs, and now we have flight tested the largest built oxide CMC structure in the world, and it performed at a very high level,” Petervary says. “Our innovative team has worked so hard to get to this point. Seeing our technology in the sky is remarkable and is a testament to what we can achieve.”

This flight demonstration is part of the five­-year U.S. Federal Aviation Admi. (FAA) Continuous Lower Energy, Emissions and Noise (CLEEN) program. Boeing is one of five industry contractors participating in CLEEN, an open, competitively bid, cost share program focused on speeding up development of new technologies that improve airplane fuel efficiency and decrease emissions and noise.

“The nozzle is a great example of how we develop and mature technology solutions faster. The team performed extremely well, and the testing completed without a hitch,” says Craig Wilsey, Boeing’s CLEEN program manager. “We really moved the needle on a technology that can benefit everyone.”

“The FAA CLEEN Program is very excited to see Boeing’s ceramic matrix composite exhaust nozzle fly,” says Arthur Orton, FAA CLEEN program engineer. “The flight test of the CMC nozzle is a major milestone for this technology. Innovative technologies such as this are needed to help meet FAA’s NextGen environmental goals, and represents excellent progress for the CLEEN Program.”

Modern engines have higher operating temperatures to achieve improved fuel efficiency and reduce emissions. However, these hotter temperatures are pushing the capabilities of current metallic components used. CMC technology is lighter than current metallic components and can last longer at higher temperatures. Special CMC designs are also capable of having acoustic treatments built into them that help make engines quieter, lighter and more efficient. This technology can also enable new, dramatically different engine designs in the future.

Later this summer, the 787 is scheduled to flight test more than 30 additional ecoDemonstrator technologies aimed at improving operational efficiency, reducing fuel use and achieving quieter operation. The ecoDemonstrator program is Boeing’s development and test program that focuses on improving environmental performance by bringing new technologies, materials and methods to implementation faster than ever before.