Abstract: A by-pass turbofan gas turbine engine, has a by-pass fan, a generally annular core engine duct, a generally annular by-pass duct situated in a generally coaxial relationship with the core engine duct coupled to the by-pass fan, an upstream axial compressor coupled to the core engine duct, a downstream radial compressor coupled to the upstream compressor, a generally annular recuperator with a cool side inlet coupled to the downstream compressor, a generally annular combustor coupled to a cool side outlet of the recuperator, a radial turbine coupled to the combustor and a warm side inlet of the recuperator coupled to the radial turbine, at least one exhaust nozzle coupled to a warm side outlet of the recuperator that discharges into the by-pass duct and a propelling nozzle coupled to the by-pass duct.

Abstract: A by-pass turbofan gas turbine engine, comprises: a by-pass fan with a by-pass fan outlet; a generally annular core engine duct with a core engine duct inlet coupled to the by-pass fan outlet and a core engine duct outlet; a generally annular by-pass duct situated in a generally coaxial relationship with the core engine duct with a by-pass duct inlet coupled to the by-pass fan outlet and a by-pass duct outlet; an upstream axial compressor with an axial upstream compressor inlet coupled to the core engine duct outlet and an axial upstream compressor outlet; a downstream radial compressor with an axial downstream compressor inlet coupled to the upstream compressor outlet and a radial downstream compressor outlet; a generally annular recuperator with a cool side inlet coupled to the downstream compressor outlet, a cool side outlet, a warm side inlet and a warm side outlet; a generally annular combustor with a combustor inlet coupled to the recuperator cool side outlet and a combustor outlet; a radial turbine wit