Turbine engine exhaust duct system and methods for noise dampening and attenuation

An exhaust attenuation assembly to receive exhaust gas from a gas turbine attached to a trailer, the exhaust attenuation assembly comprising:

• a lower elongated plenum having a proximal end and a distal end, the lower elongated plenum extending a first distance between the proximal end and the distal end, and having an inlet positioned adjacent the proximal end to receive exhaust gas from the gas turbine;
• an upper noise attenuation system movably connected relative to the distal end of the lower elongated plenum, the upper noise attenuation system being selectively movable between a stowed position, in which an outlet end portion of the upper noise attenuation system is positioned proximate the distal end of the lower elongated plenum, and an operative position, in which the upper noise attenuation system defines an upper elongated plenum in fluid communication with the distal end of the lower elongated plenum and in which an outlet of the upper elongated plenum is spaced away from the distal end of the lower elongated plenum at a second distance that is greater than the first distance, the upper noise attenuation system also including a pair of opposed silencer hoods, each of the pair of opposed silencer hoods including a planer surface having opposed side edges and a pair of opposing side surfaces that extend outwardly from portions of respective side edges of the planer surface, each of the pair of opposed silencer hoods configured to be mounted to portions of the distal end of the lower elongated plenum, and in the operative position, the pair of opposed silencer hoods being positioned substantially upright such that the planer surfaces of the respective side edges are in parallel opposition and that respective side surface are also in parallel opposition to form the upper elongated plenum;
• and
• an extension assembly disposed on the lower elongated plenum that moves the upper noise attenuation system between the stowed position and the operative position.