Large Eddy Simulation of the Transitional Flow Around the SD7003 Airfoil and Application to Blade–Vortex Interaction

The transitional flow around the SD7003 airfoil at α=8∘, Re =60,000 and Ma =0.2 was investigated employing p-adaptive large eddy simulations in a Discontinuous Galerkin (DG) framework. This test case is particularly challenging since a laminar separation bubble (LSB) with transition and reattachment of the turbulent boundary layer has been observed. The results obtained with the dynamic anisotropic model have been compared with experimental measurements and other numerical results available in literature. The polynomial adaptivity technique confirmed its capability to correctly represent the flow with a great saving in the computational cost. The results are close to experimental measurements thanks to the capability of the subgrid model to capture the energy backscatter from the subgrid scales. Starting from the statistically steady state flow field obtained, the viscous, parallel, Blade-Vortex Interaction (BVI) has been studied in the same numerical framework. A modelled vortex has been superimposed to the developed flow around the SD7003 airfoil and the dynamic p-adaptivity has been successfully employed to capture its advection over time. The loads have been recorded and compared with a reference simulation without the vortex. While the drag rapidly comes back to its steady-state value, the transients for lift and moment coefficients are longer because of the effect of the vortex on the LSB.