Patent ID: 7594388

Claim:
A turbofan engine comprising: a fan, compressor, combustor, high pressure (HP) turbine (HPT), and multistage low pressure (LP) turbine (LPT) joined in serial flow communication for sequentially pressurizing air in said fan and compressor to generate combustion gases in said combustor from which energy is extracted in said HPT and LPT; said compressor being joined to said HPT by a first rotor, and said fan being joined to said LPT by a second rotor; said HPT including two stages of HP rotor blades therein joined to said first rotor, with the second stage HP blades having an acute twist angle to effect a corresponding acute angle exit swirl in said combustion gases discharged therefrom; a transition duct disposed between said HPT and LPT, and including a row of fairings extending radially in span between radially outwardly inclined outer and inner platforms for channeling said combustion gases from said HPT to said LPT with corresponding acute swirl; said LPT including a first stage LP nozzle directly following said transition duct and being higher in radial elevation than said second stage HP blades, and having a row of first stage LP vanes extending radially in span between outer and inner bands, and followed in turn by a row of first stage LP blades joined to said second rotor; and said LP blades being oriented oppositely to said HP blades for counterrotating said first and second rotors.