OVERALL COOLING EFFECTIVENESS ON A GAS TURBINE VANE WITH SWIRL-FILM COOLING

Numerical calculation of conjugate heat transfer is carried out to study the effect of combined film and swirl cooling at the leading edge of a gas turbine vane with a a cooling chamber inside, in which 3-D steady RANS approach with the k-omega SST turbulence model is used. Two different kinds of coolant chamber configuration (C1 and C2) are selected. In C2, the cooling chamber is composed of a front cavity and a back cavity, and the two cavities are connected by a passage which is divided into 16 segments. The comparative investigations between C1 and C2 cases have been carried out to study the effect of different cooling chambers at M=0.25, 0.5, 1 and 2. For two cases, overall cooling effectiveness increases with M increasing. In Cl case, with increasing M, differences of mass flow through film holes rows will decrease. The variation of mass flow from holes changes by less than 26.7% at M=2. However,in C2 case, mass flow through S1 and S2 is significantly larger than that through other film holes rows. Area-averaged overall effectiveness in C2 is larger by 2.5% at M=0.25 compared to C1 case.