The majority of the generated noise is produced when combining the flow of hot air moving within the combustion chamber with the air on the outside. The purpose of chevrons is to make this mixture as soft as possible in such a way that noise is reduced.
This technology is currently only being used by the American manufacturer Boeing but its patent will eventually be sold to others.
The use of this technology also accounts for the decrease in noise insulation used in aeroplanes. For example, in the case of the B777, this reduction goes up to 270 kilograms, which also generates a substantial fuel saving.
An additional technological advance associated with chevrons is the use of memory foam materials. This makes the cover of the engine change its shape as temperature varies, so that the take off and landing phases are much more efficient. Once engines are cruising, it becomes colder and returns to its original shape.
Boeing 787 Dreamliner, the 777X and 737 Max were the first aircraft to incorporate this novel technology.