Gas turbine engine airfoil cooling configuration with pressure gradient separators

Abstract

An airfoil for a gas turbine engine includes an airfoil including spaced apart pressure and suction side walls joined at leading and trailing edges to provide an exterior airfoil surface that extends in a radial direction from a platform to a tip. A cavity is provided between the pressure and suction side walls near the trailing edge. The cavity includes an interior region bounded by first and second exit regions arranged at angle relative to one another. The first and second exit regions are respectively in low and high pressure regions relative to one another. First and second pedestal groups respectively are arranged at the first and second exit regions. The second pedestal group has first and second pedestals each terminating in an end. The ends of the second pedestals extend beyond the ends of first pedestals.

What is claimed is: 
     
       1. An airfoil for a gas turbine engine comprising:
 an airfoil including spaced apart pressure and suction side walls joined at leading and trailing edges to provide an exterior airfoil surface extending in a radial direction from a platform to a tip; 
 a cavity provided between the pressure and suction side walls near the trailing edge, the cavity includes an interior region bounded by a first exit region at the trailing edge and a second exit region at the tip, the first and second exit regions arranged at angle relative to one another, the first and second exit regions are respectively in low and high pressure regions relative to one another; and 
 first and second pedestal groups respectively arranged at the first and second exit regions, the second pedestal group has first and second pedestals each terminating in an end, the ends of the second pedestals extend beyond the ends of first pedestals, the second pedestals are longer than the first pedestals and in that the second pedestal group is recessed from the tip. 
 
     
     
       2. The airfoil according to  claim 1 , wherein the airfoil is a blade. 
     
     
       3. The airfoil according to  claim 1 , wherein the airfoil extends from the leading edge to the trailing edge in a chord-wise direction, the cavity is provided in at least the last 20% of the airfoil near the trailing edge in the chord-wise direction. 
     
     
       4. The airfoil according to  claim 3 , wherein the interior region includes a third pedestal group interconnecting the pressure and suction sidewalls. 
     
     
       5. The airfoil according to  claim 1 , wherein the first pedestal group is recessed from the trailing edge or extending to the trailing edge. 
     
     
       6. The airfoil according to  claim 1 , wherein a natural flow direction extends from the interior region to the first exit region, and a desired flow direction extends from the interior region to the second exit region, and the ends of the second pedestals extend beyond the ends of first pedestals in the desired flow direction. 
     
     
       7. The airfoil according to  claim 6 , wherein the natural flow direction corresponds to an aft direction in the chord-wise direction. 
     
     
       8. The airfoil according to  claim 7 , wherein the desired flow direction corresponds to the radial direction. 
     
     
       9. The airfoil according to  claim 1 , wherein the first and second pedestals include first and second lengths respectively and first and second widths respectively, the first and second lengths greater than their corresponding first and second widths. 
     
     
       10. The airfoil according to  claim 9 , wherein the first and second pedestals are in alternating relationship with one another. 
     
     
       11. The airfoil according to  claim 10 , wherein at least one first pedestal is arranged between adjacent second pedestals. 
     
     
       12. The airfoil according to  claim 9 , wherein the first length has a ratio relative to the first width of 1<L 1 /W 1 <20 and the second length has a ratio relative to the second width of 1<L 2 /W 2 <20. 
     
     
       13. A component for a gas turbine engine comprising:
 a structure including spaced apart walls that provide an exterior surface extending in first and second directions to first and second edges, respectively; 
 a cavity provided between the walls near the first and second edges, the cavity includes an interior region bounded by first and second exit regions arranged at angle relative to one another that terminate at the first and second edges arranged at an angle in a range of 60°-120°, the first and second exit regions respectively in low and high pressure regions relative to one another; 
 first and second pedestal groups respectively arranged at the first and second exit regions, the second pedestal group has first and second pedestals each terminating in an end, the ends of the second pedestals extend beyond the ends of first pedestals; and 
 wherein the first and second pedestals include first and second lengths respectively and first and second widths respectively, the first and second lengths greater than their corresponding first and second widths, wherein the first and second pedestals are in alternating relationship with one another, the second pedestals are longer than the first pedestals and in that the second pedestal group is recessed from the second edge. 
 
     
     
       14. The component according to  claim 13 , wherein first and second edge are arranged at about 90° relative to one another. 
     
     
       15. The component according to  claim 13 , wherein at least one first pedestals is arranged between adjacent second pedestals. 
     
     
       16. The component according to  claim 13 , wherein the first pedestal group is recessed from the first edge. 
     
     
       17. The component according to  claim 13 , wherein the structure is one of a vane, a blade, a blade outer air seal, a combustor liner or an exhaust liner. 
     
     
       18. The component according to  claim 17 , wherein the structure is an airfoil of a blade. 
     
     
       19. The component according to  claim 13 , wherein a natural flow direction extends from the interior region to the first exit region, and a desired flow direction extends from the interior region to the second exit region, and the ends of the second pedestals extend beyond the ends of first pedestals in the desired flow direction.