Abstract

Numerical study of hole shape effect on blade adiabatic cooling effectiveness has been carried out
on four geometry models of a standard cylindrical hole, a cylindrical hole with an upstream ramp, a
shaped diffuser, and a double console slot. In all cases, the hole centerline has an inclination angle of
35 degrees against the mainstream gas flow. Results of the cylindrical hole model are in good
agreement with available experimental and numerical data. For three hole geometry variants
considered, it was found that the cooling effectiveness has been considerably enhanced by a max
factor of 2, compared to that from the base model. The physical mechanism for this is mainly due to
the weakening of coolant flow penetration in the vicinity of the hole exit, thus reduces the level of
mixing and the entrainment with the surrounding hot gas flow.