Abstract: A gas turbine engine includes, in flow series arrangement, a mixer, a compressor, a first flow path of a recuperator, a combustor, a turbine and a second flow path of said recuperator; and a bypass conduit between said turbine and said mixer. A valve is disposed in the conduit and is controlled by a temperature sensor mounted to sense compressor inlet air temperature. The sensor has a set point temperature that corresponds with optimum emissions from the engine. When the sensed temperature drops below the set point temperature the valve opens and hot air from the turbine flows to the mixer where it heats the air entering the compressor. A method for operating a gas turbine engine with preselected emissions over a range of ambient conditions is also disclosed.

Abstract: A fuel cell stack comprises a plurality of planar fuel cells in a spiral configuration. The fuel cells angularly offset from one another such that immediately adjacent cells only partially overlap one another. The cells are preferably of the unitized type. A manifold assembly is operatively adjacent to the fuel cells. The manifold assembly includes an inlet manifold and an outlet manifold for each of the gases that are in communication with the fuel cells.