Transition Model Validation Using Unsteady Data from a Pitching Forward-Swept Laminar Wing in Transonic Flow at High Reynolds Numbers

Kurzfassung

This paper presents coupled CFD-CSM computations to validate the predictive capabilities of the DLR \gamma transition model for the unsteady aerodynamics of wings. The investigation is based on data for a pitching forward-swept natural laminar flow wing tested in the ETW at high Reynolds and Mach numbers. Due to a cavity at the wing root, a complex flow exists at the wing-fuselage intersection. To obtain a correct base flow, an effusion mass flux boundary condition is applied in the cavity. Once a good approximation of the base flow is found, the unsteady pressure coefficients are well predicted. An observed difference in phase is most likely due to wind tunnel effects not captured in the computational setup. The presented data indicate that the DLR \gamma transition model has the same predictive quality as the underlying turbulence model for unsteady aerodynamics in the flow regime investigated.