Modeling of Turbulence Drag Reduction with Riblets

A numerical simulation with RANS method in riblets drag reduction is performed in this paper. Inspired by the roughness model, modeling of the riblets is developed about ω in k-ω SST turbulence model. Based on current experimental data, a simplified method to reproduce an up-shift of the logarithmic region is proposed to represent the drag-reduction behavior of riblets in the wall region. Pressure gradients and geometry curvature are modeled in the establishment for realistic configurations by introducing the Clauser parameter β. The results show that the modeling method could simulate the drag and flow mechanism. By comparing with the experiment database on airfoils with riblets, it’s proved that the modeling can predict the drag reduction in complicated wall boundary conditions and adverse pressure gradient. Cases are provided for the estimate of riblets drag reduction in engineering applications.