Turbulence modeling for low pressure turbine blades

Laminar o w separation from Low Pressure Turbine (LPT) blades at low operating Reynolds numbers can limit the operating envelope of jet engines. After separating from the suction side of the blade, the o w transitions to turbulence and may or may not reattach. Many intriguing questions about the interaction between separation and transition still remain unanswered, complicating any turbulence modeling eort. When the Reynolds number is low enough, the o w lends itself to Direct Numerical Simulations (DNS). Twodimensional Reynolds-Averaged Navier-Stokes (RANS) calculations promise to be a low cost alternative to DNS. They may also allow for computations at Reynolds numbers too high for DNS. Turbulence modeling of transitional o ws is still an unresolved issue. In this paper, dieren t turbulence models will be employed for predicting the separating and transitional o w on an LPT blade. In addition, results from an Implicit Large Eddy Simulation (ILES) and a Flow Simulation Methodology (FSM) simulation are presented. The numerical results are compared with experimental data.

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