Abstract: A compact single shaft gas turbine engine includes a radial compressor and a radial turbine mounted for rotation about a central axis and an axially inline disk regenerator disposed forward of the turbine. A highly efficient engine configuration minimizes energy loss along an improved gas flow path while permitting the engine to be mounted on a standard 22 inch wide farming tractor frame. Efficiency is further increased by a radial exhaust diffuser disposed between the regenerator and turbine which does not contribute substantially to engine size.

Abstract: A supersonic shock wave compressor diffuser forms a concentric annulus about a radial compressor having a central axis. Circular channels diverge with an increasing divergence angle as they extend along an arcuate longitudinal center line from an inner circumference very near the periphery of the compressor to the outer circumference of the diffuser. Shock waves may occur within the channels near the inner circumference of the diffuser or may occur within a vaneless diffusion space adjacent the periphery of the compressor and provide efficient energy conversion and reduce the velocity substantially below MACH 1 to further improve the efficiency of the subsonic diffusion downstream therefrom. A logarithmic spiral is approximated by a circular arc subtended by the channel longitudinal axes to permit recovery of angular momentum while the circular cross section of the channels permits recovery of swirl velocity energy.

Abstract: A centrifugal compressor assembly for a gas turbine engine includes an inducer section and an impeller section mounted for rotation about an axis. Because leading edges of the impeller blades are cambered, damper pads, extending perpendicular to the low pressure sides thereof also extend axially forward. Blades of the inducer section are indexed rotationally rearward of the impeller blades to improve the distribution of compression gases through the impeller section and high pressure surfaces of the inducer blades mate near their leading edges with outward surfaces of the damper pads. Because the pads and inducer blades vibrate at different frequencies, inducer blade vibrations that might otherwise cause fatigue are attenuated by contact with the damper pads. The damper pad arrangement thus permits the damping of vibrations in the inducer blades notwithstanding the indexed relationship between the inducer section and the impeller section.