Turbine blade with increased film cooling

Claim 2

In a turbomachine, an air-cooled blade comprising: a blade shell having an outer surface, first, second and third inner surfaces, and a leading edge and a trailing edge; a first cavity in said shell proximate said trailing edge and formed by said first inner surface of said shell; a second cavity in said shell remote from said trailing edge and formed by said second inner surface of said shell; a third cavity in said shell proximate said leading edge and formed by said third inner surface of said shell; means for introducing cooling air into said first cavity for cooling said first inner surface; means for introducing cooling air into said third cavity for cooling said third inner surface; a plurality of passageways formed through said trailing edge and communicating with said first cavity for efflux of a first portion of said first cavity cooling air therefrom; means for directing the remainder of said first cavity cooling air from said first cavity into said second cavity for cooling said second inner surface; and means for directing all of said cooling air delivered to said second cavity in a film from said second cavity onto said outer surface for cooling said outer surface.

Claim 3

The blade of claim 1 further comprising first and second blade ends and a pair of ribs located internally of said shell and extending between said first and second blade ends, wherein said means for introducing cooling air into said first cavity is disposed proximate said first blade end, and said means for directing said cooling air into said second cavity comprises an opening in one of said ribs disposed proximate said second blade end.

Claim 4

The blade of claim 1 further comprising a radially outward tip end and a radially inward platform wherein said means for directing said cooling air onto said outer surface comprises a plurality of spaced apertures providing communication between said second cavity and said outer surface, disposed between said tip end and said platform and substantially aligned along a radial line along said blade shell.

Claim 5

The blade of claim 3 further including a hollow impingement insert positioned within said second cavity, and said cooling air directing means directs said remainder of said cooling air initially to the interior of said insert.

Claim 6

The blade of claim 4 further including a second hollow impingement insert positioned within said third cavity.

Claim 7

An air-cooled blade for use in a turbomachine, said blade comprising: a blade shell in the shape of an airfoil having a leading edge and a trailing edge and further having an outer surface and first, second and third innEr surfaces and first and second ends; a blade platform proximate the first end of said shell; first, second and third serially spaced cavities defined respectively by said first, second and third inner surfaces of said shell and disposed respectively proximate said trailing edge, remote from said trailing edge, and proximate said leading edge; a blade closure proximate the second end of said shell for separating said cavities from an environmental atmosphere; means for introducing a first flow of cooling air through said platform into said first cavity for cooling said first inner surface; a plurality of passageways formed through said trailing edge and communicating with said first cavity for efflux of a first portion of said first cavity cooling air therefrom, means proximate said closure for directing the remainder of said first flow from said first cavity into said second cavity for cooling said second inner surface; means for directing all of said first flow delivered to said second cavity in a film from said second cavity onto said outer surface for cooling said outer surface; means for introducing a second flow of cooling air through said platform into said third cavity for cooling said third inner surface; and means for directing said second flow in a film from said third cavity onto said outer surface for further cooling said outer surface.

Claim 8

An air-cooled blade for use in a turbomachine, said blade comprising: a blade shell in the shape of an airfoil having a leading edge and a trailing edge and further having an outer surface and first, second and third innEr surfaces and first and second ends; a blade platform proximate the first end of said shell; first, second and third serially spaced cavities defined respectively by said first, second and third inner surfaces of said shell and disposed respectively proximate said trailing edge, remote from said trailing edge, and proximate said leading edge; a blade closure proximate the second end of said shell for separating said cavities from an environmental atmosphere; means for introducing a first flow of cooling air through said platform into said first cavity for cooling said first inner surface; a plurality of passageways formed through said trailing edge and communicating with said first cavity for efflux of a first portion of said first cavity cooling air therefrom, means proximate said closure for directing the remainder of said first flow from said first cavity into said second cavity for cooling said second inner surface; means for directing all of said first flow delivered to said second cavity in a film from said second cavity onto said outer surface for cooling said outer surface; means for introducing a second flow of cooling air through said platform into said third cavity for cooling said third inner surface; and means for directing said second flow in a film from said third cavity onto said outer surface for further cooling said outer surface.

Claim 9

The blade of claim 6 wherein said means for directing said first flow onto said outer surface comprises a plurality of spaced apertures substantially aligned along a radial line between said first and second ends of said blade shell.