Accession Number:

ADA218742

Title:

An Investigation of Convection Cooling of Small Gas Turbine Blades Using Intermittent Cooling Air

Descriptive Note:

Technical rept.

Corporate Author:

ARMY TANK-AUTOMOTIVE COMMAND WARREN MI

Personal Author(s):

Report Date:

1988-08-01

Pagination or Media Count:

145.0

Abstract:

This paper demonstrates that a pulsed or intermittent flow has the potential to substantially increase the convective heat transfer coefficient. The application to convection cooling of gas turbine blades and vanes is demonstrated in a test facility designed to simulate the first-stage turbine blade of the AGT 1500 gas turbine engine which powers the Armys M1 Abrams Main Battle Tank. A cylindrical test section is convectively cooled while the flow is interrupted by a rotating chopper in the range 0 to 720 Hz. Heat transfer is measured as a function of the frequency of the disturbance. The data shows an increase in heat transfer as high as 30 over the steady-flow case when air flow is held constant. The increase in heat transfer is a function of frequency, increasing generally with frequency. This was demonstrated to the limit of the present apparatus, however, it is obvious that the effect will diminish and at very high frequency will be indistinguishable from steady flow. Harmonics in the flow stream will influence the increase in heat transfer both positively and negatively. EDC

Subject Categories:

  • Air Conditioning, Heating, Lighting and Ventilating
  • Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE