AN AUTOMATIC TRANSMISSION FOR AUTOMOTIVE GAS TURBINE POWER PLANTS

In a concentrated government-industry effort to develop an automotive gas turbine power plant as an alternative to spark ignition engines, General Motors has been awarded a 68-month contract to develop an automotive gas turbine. The delivery of a fully-developed power plant in a Pontiac Phoenix front-drive vehicle is scheduled during 1985 for test and evaluation by the Environmental Protection Agency. The goal is to incorporate near-term (five-year) technology capable of a 30% improvement over fuel economy projected for a comparable conventional 1984 automotive power plant. Maximum component efficiency at very low power levels is the key to overall system performance capable of this improvement. The selection between a new continuously-variable transmission or a conventional automatic transmission (CAT) calls for critical examination of the automotive driving cycle, specific fuel/power/speed characteristics of the gas turbine engine, and transmission subsystem performance and efficiency at very low power levels. It is shown that the four-speed CAT with converter clutch and multiple fixed-gear ratio selection provides two advantages: it exhibits maximum component efficiency at very low power levels, a requirement for maximum fuel economy over a 0-60 mph Federal driving cycle; and it permits the gas turbine power train to run near the best specific fuel consumption characteristics for road load speeds of 0-60 mph. The conventional torque converter automatic transmission, with present-day technology including converter clutch variable displacement pump, low output spin losses, and overdrive gearing, is the best transmission selection for the advanced ceramic two-shaft gas turbine engine.

  • Supplemental Notes:
    • Also published in HS-028 833 (SAE-SP-465), "Advanced Gas Turbine Systems for Automobiles," Warrendale, Pennsylvania, 1980, p 1-5. Presented at SAE Congress and Exposition, Detroit, 25-29 February 1980.
  • Corporate Authors:

    Society of Automotive Engineers (SAE)

    400 Commonwealth Drive
    Warrendale, PA  United States  15096
  • Authors:
    • Polak, J C
  • Publication Date: 1980

Media Info

  • Pagination: 5 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00391485
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: SAE 800099, HS-028 834
  • Files: HSL, USDOT
  • Created Date: Dec 30 1984 12:00AM