Jet nozzle mixer

In a nozzle for a jet engine enclosed within a tubular housing and having a thrust reverser having a stowed position fixed relative to the tubular housing and having a deployed position, and also having an existing first stage mixer which includes a number of first stage lobes enclosed in said tubular housing rearward from said jet engine a method for cooling exhaust engine exhaust gases and for attenuating engine exhaust noise comprising the steps of:

• utilizing a second stage mixer coupled to the exterior of said tubular housing at an exhaust aperture of said tubular housing;
• the second stage mixer being unenclosed by a housing and having an exterior in contact with the ambient air to allow the air to enter the mixer and mix with the gas from the first stage mixer;
• the second stage mixer having a trailing edge forming the exit terminus for the gas flow;
• and said thrust reverser in the deployed position being positioned downstream of the exit terminus to reverse the gas flow;
• the second stage mixer receiving substantially all of the exhaust from the first stage mixer;
• utilizing a plurality of identically formed lobes which equal in number those of the first stage lobes;
• and configuring said lobes (a) on their interior surfaces to force impinging hot gases from the jet engine towards the interior of the second stage mixer and (b) on their exterior surfaces to mix with ambient cooling air communicated from the exterior of said tubular housing to form gas cores which are smaller than those formed by the first stage mixer and to break the smaller gas cores into innumerable forms which are both cooler and noise attenuated.

In a nozzle for a jet engine enclosed within a tubular housing and having a thrust reverser having a stowed position fixed relative to the tubular housing and having a deployed position and also having an existing first stage mixer which includes a number of first stage lobes enclosed in said tubular housing rearward from said jet engine, a method for cooling hot exhaust engine exhaust gases and for attenuating engine exhaust noise comprising the steps of:

• utilizing a second stage mixer coupled to the exterior of said tubular housing at an exhaust aperture of said tubular housing;
• the second stage mixer being unenclosed by a housing and having an exterior in contact with the ambient air to allow the air to enter the mixer and mix with the gas from the first stage mixer;
• the second stage mixer having a trailing edge forming the exit terminus for the gas flow;
• and said thrust reverser in the deployed position being positioned downstream of the exit terminus to reverse the gas flow;
• the second stage mixer receiving substantially all of the exhaust from the first stage mixer;
• and utilizing a plurality of identically formed lobes which equal in number those of the first stage lobes.