3D Investigations of Nozzle Cluster Platform Cooling in the Variant with Doubled V-Shaped Dimplesand Hemispherical Protrusions between Them and in the Variant with Ribs when the Platform Is Blowing off through the Holes in the Shield

By results of 3D calculations carried out, the computational study was fulfilled for the local and averaged heat transfer coefficients, hydrodynamic characteristics of platform cooling channels with meridional compression in the cavity between the shield and the platform for the variant with doubled V-shaped dimples with hemispherical protrusions between them as well as for the variant with ribs on the platform surface blown down through the holes in the shield over the platform. Investigations of the platform cooling efficiency for these variants are carried out.