Patent attributes
A film cooling slot arrangement for a turbine blade, in which the blade includes a suction side with an impact zone on which hot and heavy particles can strike to block film cooling holes. The impact zone includes a first row of film cooling slots extending through a lower span, a middle span and an upper span of the blade. The film cooling slots in the lower span have a plurality of metering holes with axial centers at from 20 to 40 degrees from the spanwise angle of the blade. Film cooling slots in the middle span have metering holes with axial centers at from 30 to 50 degrees from the spanwise angle. And, film cooling slots in the upper span have metering holes with axial centers at from 40 to 60 degrees from the spanwise angle. A second row of film cooling slots in the impact zone and adjacent to the first row also have lower span slots, middle span slots, and upper span slots with metering holes having the axial centers of the above described angles. Each film cooling slot includes a first diffusion slot connected downstream of the metering hole and a second diffusion slot connected downstream of the first diffusion slot to produce a multiple diffusion slot for the film cooling air.
