NACA Research Memorandums

Abstract

Memorandum presenting an investigation to devise an air-cooled turbine blade which eliminated the difficulties encountered with brazing in air-cooled-blade fabrication. Techniques were developed for casting air-cooled blades with a large number of relatively small cooling passages near the airfoil surface; two such blades of HS-21 material were operated in a turbojet engine modified for air cooling. Results regarding the heat-transfer characteristics, stress and durability results, and evaluation of cast-cored-blade potential are provided