The nozzles, which have been shown to work on 1/28th-scale jet engines, feature triangular fins like rows of shark teeth which significantly reduced jet engine noise in lab tests.
“They’re simple attachments that change the behaviour of the flow coming out of the engine with minimal effect on its performance,” said professor Ephraim Gutmark, a researcher on the project.
UC’s lab tests showed the new nozzle could reduce engine noise by five to eight decibels, a significant decrease considering decibels are measured logarithmically.
“Typically, engine companies are happy even getting a half-decibel improvement,” Gutmark said.
Hearing loss and tinnitus are the leading causes of military disability claims in the US, affecting more than 2.6 million former service members, according to the US Department of Veterans Affairs. It spends more than $1bn per year on hearing loss cases, which represent about 15 per cent of new disability claims that are filed with...