Development and Assessment of a Delayed Detached-Eddy Simulation Method for Predicting Transitional Turbomachinery Flows Under Off-Design Conditions

Kurzfassung

Reliable computational fluid dynamics methods are crucial for the aerodynamic design of next-generation turbomachinery. Leaving the aerodynamic design point, and approaching off-design conditions near stall, is still challenging for low-fidelity methods, because these operating conditions are characterized by massive separation, high unsteadiness, laminar-to-turbulent transition and their combined appearances. This motivates the application of the Delayed Detached-Eddy Simulation (DDES) method, which is further developed and assessed for transitional flows. The resulting DDES-γ model is validated analyzing academic and turbomachinery test cases. The developed DDES-γ method is an accurate analysis tool for turbomachinery flows under off-design conditions with reported limitations. Findings of this thesis support the decision process of an engine designer whether this method is appropriate for the particular question-specific application or not.