The effectiveness of two-dimensional film-cooling over curved surfaces
Abstract
This paper describes an experimental and computational investigation of the influence of longitudinal curvature on the impervious-wall effectiveness of two-dimensional film-cooling. The influence of slot height, radius of curvature, velocity ratio and density ratio have been separately examined. It is shown that decreasing the radius of convex curvature results in increasing effectiveness until flow separation. The flow tends to separate closer to the slot exit as the radius is decreased and results in a rapid fall in effectiveness. For concave curvature, there is a small reduction in the effectiveness which stems from augmentation of the near-wall turbulence intensity. An increase in slot gap tends to result in earlier separation for a convex surface and to a slight improvement in effectiveness for a concave surface. The computational investigation solves finite-difference representations of appropriate conservation equations: the turbulence model is that of a modified mixing length.
- Publication:
-
American Society of Mechanical Engineers and American Institute of Chemical Engineers
- Pub Date:
- August 1976
- Bibcode:
- 1976ceht.confR....F
- Keywords:
-
- Film Cooling;
- Flow Geometry;
- Gas Turbine Engines;
- Surface Properties;
- Two Dimensional Flow;
- Combustion Chambers;
- Conservation Equations;
- Convexity;
- Coolants;
- Engine Design;
- Graphs (Charts);
- Slots;
- Turbulence Models;
- Fluid Mechanics and Heat Transfer