Freestream Deceleration Effects on Film Cooling Over a Flat Plate
Abstract
Film cooling is a method used within gas turbines to cool the turbine blades by blowing air out of small holes in the blade surface of the blades. This allows the gas turbine to be run at higher internal temperatures, increasing the efficiency and power output of the engine. Regions of the curved turbine blade cause the freestream air flowing around it to accelerate and decelerate. This study seeks to determine the effects of this freestream deceleration on film cooling. The experiments accomplish this by using a flat plane with circular, angled holes in the surface to model a small portion of the gas turbine blade. Measurements were made for a zero acceleration case, and two decelerated cases at acceleration parameters (K), a non-dimensional value representing acceleration magnitude, of -0.5010(exp -6) and -0.6810(exp -6). Three different blowing ratios (M), ratios of the coolant jet velocity to the freestream airflow velocity, were studied in each case. Results show that freestream deceleration has little to no effect on film cooling effectiveness and Stanton number ratio. This information increases understanding of film cooling and allows models to be made more accurate.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 12, 2021
- Accession Number
- AD1149673
Entities
People
- Matthew C. Gillcrist
Organizations
- United States Naval Academy