The findings in this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. When Government drawings, specifications, or other data are used for any purpose other than in connection with a definitely related Government procurement operation, the U. S. Government thereby incurs no responsibility nor any obligation waatsoever; and the fact that the Government may have formulated, furnished, or in any way supplied the said drawings, specifications, or other data is not to be regarded by implication or otherwise as in any manner licensing the holder or any other person or corporation, or conveying any rights or permission, to manufacture, use, or sell any patented invention that may in any way be related thereto. DISPOSITION INSTRUCTIONS Destroy this report when no longer needed, inator. Do not return it to the origtamm m " tftn mnustmd DM uffwetmo uiuxaweci D m'.nmm w i iwiiirion/iMiuM'n CVKJ £-Unclassified b

The design of a high-temperature, high-work radial turbine for advanced small gas turbine engines is described. This turbine is designed to produce nearly 220 Btu/lb gas flow at 87.5% efficiency, with a 5:1 stage pressure ratio. Turbine inlet gas conditions are 17.5 atm and 2300°F. The resulting turbine configuration includes an air-cooled, 12-bladed rotor designed for 67,000 rpm, and a 20-vaned, air-cooled nozzle section of a reflex (supersonic) design. Both parts are IN 100 (PWA 658) investment castings. The discussion includes results of aerodynamic, structural, and thermal analyses. Also discussed is a fabrication study, which indicated that a casting development effort would be required to produce adequate material properties. This effort is currently underway, and consists of both an integral centrifugal casting approach and a bicasting technique. The test rig to be used for the turbine tests is described.

No abstract

A current NASA-sponsored contract will develop attachment technology for hybrid turbine rotors having dovetailed ceramic ceramic blades and a wrought metal disk. The approach and sequence of activities are described in detail. The program scope includes design, fabrication, and spin testing of hot-pressed silicon nitride blades for operation at rotor inlet temperatures of 2192 F (1200 C) or greater.