Efficient Simulation Framework for High-Reynolds-Number Flows over Riblet Configurations

Due to the significant disparity between inner and outer flow scales, numerical simulation that directly resolves the near-wall flow in riblet grooves on complex aeronautical configurations is not feasible for aircraft. To balance the accuracy and computational cost, a Reynolds-averaged Navier–Stokes simulation framework based on a data-driven slip-velocity boundary condition model is developed for the simulation of turbulent flows over riblet surfaces. The relationship between the local slip-velocity condition, external flow characteristics, and the riblet geometry is derived by integrating experimental data with theoretical analysis. Drag reduction is predicted by incorporating the physical length scales of riblets and external flow conditions into the framework. The model is validated through simulations of turbulent flows over flat plates, NACA0012 airfoils, and DU 96-W-180 airfoils covered by riblets, showing accurate predictions of both friction and pressure drag reduction. Finally, the framework is utilized to simulate turbulent flows around an M6 wing with riblets. A total drag reduction of 3.3% is predicted at an angle of attack of 3.06° for V-shaped riblets with a spacing of 10 μm. This framework provides an efficient tool for predicting drag reduction on ribbed complex surfaces without explicitly simulating the near-wall flow.