Jet engine noise suppressor

[Tom Sanderson]

> Can anyone tell me how a noise suppressor for a turbojet engine works?

Most of the noise from a turbojet comes from shearing between the high-speed
hot exhaust jet and the stationary cool ambient air. Most of the noise
suppressors (aka hush-kits) are designed to promote rapid mixing of the jet
with the ambient air to reduce the shearing. It's a sort of a hack-job way
of taking the high-speed low mass exhaust jet and turning it into a
low-speed high mass air flow. This is part of why turbofans are much much
quieter.

Tom.