General Motors Corporation

ABSTRACT:
ATTAP activities during the past year were highlighted by an extensive materials assessment, execution of a reference powertrain design, test-bed engine design and development, ceramic component design, materials and component characterization, ceramic component process development and fabrication, component rig design and fabrication, test-bed engine fabrication, and hot gasifier rig and engine testing. Although significant technical challenges remain, all areas experienced progress. Materials assessment activities entailed engine environment evaluation of domestically supplied radial gasifier turbine rotors that were available at the conclusion of the Advanced Gas Turbine (ACT) Technology Development Project as well as an extensive survey of both domestic and foreign ceramic suppliers and Government laboratories performing ceramic materials research applicable to advanced heat engines. A reference powertrain design was executed to reflect the selection of the AGT-5 as the ceramic component test-bed engine for the ATTAP. Test-bed engine development activity focused on upgrading the AGT-5 from a 1038 degrees C (1900 degrees F) metal engine to a durable 1371 degrees C (2500 degrees F) structural ceramic component test-bed engine. Ceramic component design activitie1 included the combustor, gasifier turbine static structure, and gasifier turbine rotor. The materials and component characterization efforts have included the testing and evaluation of several candidate ceramic materials and components being developed for use in the ATTAP. Ceramic component proce1a development and fabrication activities were initiated for the gasifier turbine rotor, gasifier turbine vanes, gasifier turbine scroll, extruded regenerator disks, and thermal installation. Plans for 1989 include delivery of gasifier turbine rotors, vanes and scrolls, injection moldable thermal insulation, and extruded regenerator matrix samples. Component rig development activities included combu1tor, hot ga1ifier, and regenerator rigs. Test-bed engine fabrication activities consisted of the fabrication of an all-new AGT-5 durability test-bed engine and support of all engine test activities through instrumentation/build/repair. Hot gasifier rig and test-bed engine testing activities were performed.… (més)

ABSTRACT:
Engine testing, ceramic component fabrication and evaluation, component performance rig testing, and producibility experiments at Pontiac comprised AGT 100 activities of this period, January-December 1984. Two experimental engines were available and allowed the evaluation of eight experimental assemblies. Operating time accumulated was 115 hr of burning and 156 hr total. Total cumulative engine operating time is now 225 hr. Build number 11 and 12 of engine S/N l totaled 28 burning hours and constituted a single assembly of the engine core--the compressor, both turbines, and the gearbox. Build number 11 of engine S/N l included a 1:07 hr continuous test at 100% gasifier speed (86,000 rpm). Build number 8 of engine S/N 2 was the first engine test with a ceramic turbine rotor. A mechanical loss test of an engine assembly revealed the actual losses to be near the original design allowance. Component development activity included rig testing of the compressor, combustor, and regenerator. Compressor testing was initiated on a rig modified to control the transfer of heat between flow path, lubricating oiI and structure. Results show successful thermal decoupling of the rig and lubricating/cooling oil. Rig evaluation of a reduced-friction compressor was initiated. Combustor testing covered qualification of ceramic parts for engine use, mapping of operating range limits, and evaluation of a relocated igniter plug. Several seal refinements were tested on the hot regenerator rig. An alternate regenerator disk, extruded MAS, was examined and found to be currently inadequate for the AGT 100 application. Also, a new technique for measuring leakage was explored on the regenerator rig. Ceramic component activity has focused on the development of state-of-the-art material strength characteristics in full- seal e hardware. Injection-molded sintered alpha-SiC rotors were produced at Carborundum in an extensive process and tool optimization study. Correlation of spin-to-burst rotor tests with fracture surface analyses revealed that backface flow and knit-line indications were the frequent cause of rotor bursts at relatively low speeds. A modified fabrication/rework procedure, for both green and sintered rotors, was identified whereby these surface imperfections may be removed. The exploration of injection molded GTE Si3N4 rotors included evaluation of 10 hot isostatically pressed (HIP) rotors. Burst testing demonstrated that HIP processing raised burst speed. Gasifier turbine scroll assemblies, in SiC material, are being fabricated by both Carborundum and Norton. Carborundum units are awaiting hot-rig test; engine test will follow successful rig testing. Fiber reinforced glass-ceramic composite turbine backplates were fabricated by the Corning Glass Works. Different materials were considered, and evaluation was initiated with room temperature bend testing of test bars.… (més)

ABSTRACT:
Technical work on the design of a 74.5 kW (100 hp) advanced automotive gas turbine engine is described for the period July through December 1980. This is the second semi-annual report. Work this period was directed toward refining the engine design and starting component rig tests. A design iteration to improve the weight and production cost associated with the original concept is discussed. Major rig tests included 15 hours of compressor testing to 80% design speed and the results are presented. Approximately 150 hours of cold flow testing showed duct loss to be less than the design goal. Combustor test results are presented for initial checkout tests. Turbine design and rig fabrication is discussed. From a materials study of six methods to fabricate rotors, two have been selected for further effort. A discussion of all six methods is given.… (més)

ABSTRACT:
This report presents a technical summary of the Detroit Diesel Allison (DDA) project to develop an automotive gas turbine powertrain system under NASA Contract DEN 3-168 (Department of Energy funding). It covers the 9-month period October 1979 through June 1980. Future reports will cover 6-month periods.

The basic objective of this project is to develop and demonstrate, by May 1985, an advanced automotive gas turbine powertrain system that will, when installed in a 1985 Pontiac Phoenix vehicle of 1360 kg (3000 1 bm) inertia weight, achieve a fuel economy of 18 km/L (42.5 mpg), meet or exceed the 1985 emission requirements, and have alternate fuel capability.

Several General Motors Divisions and other companies are major contributors to this effort. They are: Pontiac Motor Division--vehicle, Delco Electronics Division--electronic control, Harrison Radiator Division and Corning Glass Works--regenerator, Hydra-Matic Division--transmission, The Carborundum Company and GTE--ceramics.

The DDA Program Manager for the AGT 100 is H. E. Gene Helms; design effort is directed by James Williams; materials effort is directed by Dr. Peter Heitman and project effort is directed by Richard Johnson. The Pontiac effort is headed by J. Kaufeld, and the Delco Electronics work is managed by Robert Kordes. The NASA AGT 100 Project Manager is Paul T. Kerwin and Assistant Project Manager is James Calogeras.… (més)