Leading-edge geometry effects on the vortex system formation of a diamond wing configuration

The effects of span-wise varying leading-edge contours with respect to vortex system formation are investigated on a diamond wing configuration named SAGITTA. Both steady and unsteady Reynolds-Averaged Navier-Stokes equations are applied to compute numerical results for three different leading-edge configurations at low speed conditions. The cases differ in the span-wise leading-edge contours that can be of sharp or rounded type. The vortex system formation on the SAGITTA diamond wing configuration is dependent on the chosen leading-edge contours, resulting in diverse flow topologies. Both the flow topologies as well as the characteristics of the aerodynamic coefficients and surface pressure coefficient distributions are discussed in detail for the three analyzed configurations. Due to the 12% relative thickness airfoil, vortex system formation only takes place at sharp leading-edge segments, but not for rounded leading-edge contours. Despite diverse flow topologies, however, the resulting effects on global performance regarding lift and pitching moment characteristics are found to be only small for the regarded configurations.