Turbulence modeling and computation of viscous transitional flows for low pressure turbines

Variation of the flow Reynolds number between the take off and cruise condi tions significantly affects the boundary layer development on low-pressure turbine blading. A decreased Reynolds number lends to the flow separation o n the suction surface of the blading and increased losses. A numerical simu lation has been carried out to assess the ability of a Navier-Stokes solver to predict transitional flows in a wide range of Reynolds numbers and inle t turbulence intensities. A number of turbulence models (including the Alge braic Reynolds Stress Model) and transition models have been employed to an alyze the reliability and accuracy of the numerical simulation. A compariso n between the prediction and the experimental data reveals good con elation . However, the analysis shows that the artificial dissipation in the numeri cal solver may have a profound effect on the prediction of the transition i n a separated flow.