Chevrons are the sawtooth edges found on the edges of jet engine nacelles and/or nozzles. They are proven to reduce engine noise outside and inside the cabin.
During the 1990s and early 2000s, NASA computer simulations provided the latest improvements in design for chevrons, helping the aviation community decide which chevron shapes would be most effective. Then, ground and flight tests by NASA and its partners proved that the new design reduced noise levels in the passenger cabin and on the ground.
According to industry partner Boeing, engines with chevrons on their 787 aircraft result in a 69% smaller noise footprint, and 29% smaller on the 747-8.
