EFFECT OF SQUEALER TIP ON ROTOR HEAT-TRANSFER AND EFFICIENCY

Calculations were preformed to simulate the tip flow and heat transfer on the GE-E-3 first-stage turbine, which represents a modern gas turb ine blade geometry. Cases considered were a smooth tip 2 percent reces s, and 3 percent recess. In addition, a two-dimensional cavity problem was calculated. Good agreement with experimental results was obtained for the cavity calculations, demonstrating that the k-omega turbulenc e model used is capable of representing flows of the present type. In the rotor calculations, two dominant flow structures were shown to exi st within the recess. Also areas of large heat transfer rate were iden tified on the blade tip and the mechanisms of heat transfer enhancemen t were discussed. No significant difference in adiabatic efficiency wa s observed for the three tip treatments investigated.