Computations from the Fourth Drag Prediction Workshop Using the Edge Solver

Abstract

Results carried out for the 4th AIAA Drag Prediction Workshop with the flow solver Edge are summarized. Simulations have been carried out for wing–body–tail configurations with three horizontal tail incidences and for one tail-off configuration. The computations consist of a grid-refinement study and a downwash study with polar calculations to explore the trimmed condition and delta effects. An investigation of the sensitivity to the grid and turbulence model is carried out from calculations on two sets of unstructured grids with three turbulence models, including the explicit algebraic Reynolds stress model, the SST model, and the Spalart–Allmaras model. The grid-refinement study, for which the flow is attached, shows rather small differences due to different grids and models. The major difference is obtained from the turbulence models where about 10 drag counts between the highest and lowest drag values are predicted, respectively, by the explicit algebraic Reynolds stress model and the Spalart–Allmaras model. The difference between the two sets of grids is only about two drag counts. The polar calculations in the downwash study also show rather small differences in which the same tendency for the drag prediction is observed as in the grid-refinement study. The largest differences between the solutions are due to different turbulence models and observed at the highest angles of attack, where the flow starts to separate after the shock on the wing.