Patent ID: 8669670

Claim:
A gas turbine engine, comprising: at least first and second turbo-compressor spools, each of the at least first and second turbo-compressor spools comprising a centrifugal compressor in mechanical communication with a radial turbine; at least one intercooler positioned in a fluid path between the at least first and second turbo-compressor spools; a recuperator operable to transfer thermal energy from an output gas of a power turbine to a compressed gas produced by the at least first and second turbo-compressor spools and thereby form a further heated gas; and a combustor operable to combust a fuel in the presence of the further heated gas; wherein: a first inlet gas to a first compressor in the first turbo-compressor spool enters the first compressor along a first axis; a first compressed gas from the first compressor exits the first compressor along a second axis; the first compressed gas to a second compressor in the second turbo-compressor spool enters the second compressor along a third axis; a second compressed gas from the second compressor exits the second compressor along a fourth axis; and wherein the second axis is rotatable about the first axis and fourth axis is rotatable about the third axis.