Patent ID: 8069647

Claim:
An engine assembly, comprising: an engine enclosed within a housing, said housing having an exhaust aperture; a first stage mixer within said housing, said first stage mixer including first stage lobes to mix exhaust gas with cooling air; a thrust reverser coupled to said housing and having a stowed position fixed relative to said housing and having a deployed position located behind said housing at a predetermined position for receiving gas flow directly from said exhaust aperture without a second stage mixer; a second stage mixer coupled to said exhaust aperture of said housing to receive gas exhausted from said first stage mixer, said second stage mixer having second stage undulating lobes having an periphery to mix exhaust gas with cooling air, said second stage mixer containing the same number of lobes as said first mixer, said second stage mixer being unenclosed by said housing and having an exterior in contact with the ambient air to allow the air to enter said second stage mixer and mix with the gas from said first stage mixer, said second stage mixer having a trailing edge forming the exit terminus for the gas flow; said bucket-type thrust reverser in the deployed position being positioned downstream of the exit terminus to reverse the gas flow; and said second stage mixer having additional mixing elements positioned at said trailing edge of said second stage mixer; wherein said additional mixing elements include a separate band surrounding the outer periphery of said undulating lobes at the said trailing edge, and said band including projections to further mix the exhaust gas.