Brittle Materials Design, High Temperature Gas Turbine

• Main Authors: McLean, Arthur F, Fisher, Eugene A, Bratton, Raymond J
• Format: Report
• Language: English
• Subjects: AERODYNAMIC LOADING; BONDING; BRITTLE MATERIALS; BRITTLENESS; CERAMIC MATERIALS; Ceramics, Refractories and Glass; COMBUSTION CHAMBERS; COMPUTER PROGRAMS; DENSITY; DESIGN; DIFFERENCE EQUATIONS; DUO-DENSITY ROTORS; EDGES; ELECTRIC POWER PRODUCTION; FABRICATION; GAS BEARINGS; GAS TURBINE ROTORS; GAS TURBINES; GUIDE VANES; HEAT TRANSFER; HIGH TEMPERATURE; INJECTION; INJECTION MOLDING; INVESTMENT CASTING; Jet and Gas Turbine Engines; MOLDING TECHNIQUES; MULTIDENSITY; NONDESTRUCTIVE TESTING; NOSE CONES; PERFORMANCE(ENGINEERING); PRESS BONDING; PRESSURE; RINGS; ROTOR BLADES(TURBOMACHINERY); SHROUDS; SILICON CARBIDES; SILICON NITRIDES; SLIP CASTING; STRESSES; THERMAL SHOCK; THREE DIMENSIONAL; TURBINE STATORS; VEHICLES

The Brittle Materials Design, High Temperature Gas Turbine program is to demonstrate successful use of brittle materials in demanding high temperature structural applications. A small vehicular gas turbine and a large stationary gas turbine, each utilizing uncooled ceramic components, will be used in this iterative design and materials development program. In the vehicular turbine project, three dimensional stress analysis programs are being developed and applied to turbine rotors and stators. Improvements have been made in the fabrication of duo density silicon nitride rotors. A major objective was reached with the completion of a 50 hr cyclic engine test of ceramic hot flow path components. A silicon carbide combustor tube was tested in a combustor rig for 50 hrs, including 6 hr at an outlet temperature of 2500 F. Non-destructive evaluation techniques have been applied to the fabrication of ceramic components resulting in the elimination of defective parts at an early stage in processing. In the stationary turbine project, considerable design effort was expended on the modification of the rotating test turbine for the high temperature testing to meet program objectives. The static test rig was rebuilt for 2500 F peak temperature operation, and five cycles were run to 2300 F to establish control parameters. A rotor blade configuration was analyzed by the three dimensional stress analysis program and the results are presented. Prepared in cooperation with Westinghouse Electric Corp., Pittsburgh, Pa.