NUMERICAL PREDICTION OF HEAT TRANSFER ON TRANSONIC TURBINE BLADES AT OFF DESIGN OPERATING CONDITIONS

摘要

The goal of this paper is to investigate the performances of the v2-f(Lien and Durbin, 1996) and ζ-f (Hanjalic et al., 2004) turbulence models in predicting the external heat transfer distribution on a high turning turbine blade working in transonic regime at off design operating conditions. The turbulent heat flux was modeled first in the hypothesis" of constant turbulent Prandtl number and secondly with the aid of the algebraic relation for turbulent thermal diffusivity of Rokni and Sunden (2003). The numerical results show that the surface heat transfer coefficient is quite correctly predicted by both turbulence models in all the regions were the boundary layer is fully turbulent. Despite the realizable condition of Durbin, at the stagnation point the heat transfer rate remains over-predicted when the Pr{sub}t=const. hypothesis is used, but the algebraic relation of Rokni and Sunden fixes this problem. Unfortunately, the boundary layer transition is simulated too early by both turbulence models, which also have some difficulties in predicting the real shock wave structure.