Gas turbine mixer apparatus

Mixing apparatus for mixing first and second fluid streams with one another wherein said first fluid stream flows through an inner duct and said second fluid stream flows through an annular passageway formed between said inner duct and an outer duct that coaxially surrounds said inner duct, the direction of fluid flow of said first and second fluid streams substantially being in the same axial direction relative to said coaxially arranged inner and outer ducts, said outer duct extending axially in the direction of fluid flow beyond the terminus of said inner duct to define a common duct for the mixing of said first and second fluid streams, said mixing apparatus comprising:

• an annular free mixer mountable to said terminus of said inner duct to extend in said axial direction of fluid flow, said annular free mixer having a cross-sectional geometry at the forwardmost end thereof substantially corresponding to the cross-sectional geometry of said terminus of said inner duct, said annular free mixer having a smoothly contoured terminating edge for permitting those regions in said first and second fluid streams flowing contiguous with the boundaries of said free mixer to partially mix with one another as said contiguous regions flow past said terminating edge of said free mixer;
• a plurality of axially extending members projecting rearwardly from said terminating edge of said free mixer, said plurality of axially extending members being circumferentially spaced-apart from one another along said terminating edge of said annular free mixer, said plurality of axially extending members defining a plurality of axially extending open regions between adjacent ones of said axially extending members, said plurality of axially extending members being configured and arranged to define the transverse cross-sectional geometry of said plurality of open regions as segments between two concentric, geometric closed curves with each of said axially extending members forming a boundary wall that separates one of said open regions from an adjacent one of said open regions to thereby collectively define said plurality of open regions;
• means for inducing a component of outward radial flow of said first fluid stream through a first plurality of said axially extending open regions and for inducing a component of inward radial flow of said second fluid stream through a second plurality of said axially extending open regions, said radially induced flow of said first fluid stream penetrating into said second fluid stream and said radially induced flow of said second fluid stream penetrating into said first fluid stream, individual open regions of said first plurality of open regions for outward radial flow of said first fluid stream being interspersed in circumferential alternation with individual open regions of said second plurality of open regions for inward radial flow of said second fluid stream, said means for inducing said radial flow of said first and second fluid streams including a plurality of deflection vanes mounted transversely within individual open regions of at least one of said first and second pluralities of axially extending open regions, said plurality of deflection vanes mounted within said individual open regions to extend between adjacent ones of said circumferentially spaced-apart, axially extending members, said deflection vanes being spaced-apart from one another along said axially extending members and canted relative to the axial flow direction of said first and second fluid streams, said deflection vanes being canted to expose the forwardmost boundary of each of said deflection vanes with that one of said first and second fluid streams being induced to include a radial flow component.