Prediction of Transonic Buffet by Delayed Detached-Eddy Simulation

Fernando Grossi (1) , Marianna Braza (1) , Yannick Hoarau (2)

1 IMFT - Institut de mécanique des fluides de Toulouse
2 ICube - Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie

A delayed detached-eddy simulation of the transonic buffet over a supercritical airfoil is performed. The turbulence modeling approach is based on a one-equation closure, and the results are compared to an unsteady Reynolds-averaged Navier–Stokes simulation using the same baseline model as well as experimental data. The delayed detached-eddy simulation successfully predicts the self-sustained unsteady shock-wave/boundary-layer interaction associated with buffet. When separation occurs, the flow exhibits alternate vortex shedding and a spanwise undulation. The method also captures secondary fluctuations in the boundary layer that are not predicted by unsteady Reynolds-averaged Navier–Stokes simulation. A map of flow separation emphasizes the differences between the delayed detached-eddy simulation and unsteady Reynolds-averaged Navier–Stokes flow topologies. Statistical pressure distributions and velocity profiles help assess the performance of each model. They indicate that the delayed detached-eddy simulation tends to overestimate the flow unsteadiness near the trailing edge. Instantaneous distributions of Reynolds-averaged Navier–Stokes and large-eddy simulation regions during buffet show that the delayed detached-eddy simulation enforces Reynolds-averaged Navier–Stokes mode near the airfoil even when the boundary layer gets very thick.

Mots clés: Turbulence

Domaines: Mécanique des fluides [physics.class-ph]

Fernando Grossi, Marianna Braza, Yannick Hoarau. Prediction of Transonic Buffet by Delayed Detached-Eddy Simulation. AIAA Journal, 2014, 52 (10), pp.2300-2312. ⟨10.2514/1.J052873⟩. ⟨hal-03466767⟩