The effects of spanwise-varying leading-edge contours with respect to vortex formation are investigated on a diamond-wing configuration named SAGITTA. At low-speed conditions, three different leading-edge configurations are considered for which the spanwise leading-edge contours can be of a sharp or rounded type. In a combined approach, both numerical computations and experimental investigations are therefore conducted. On the one hand, both steady and unsteady Reynolds-averaged Navier–Stokes equations are applied to compute numerical results for all three different leading-edge configurations. On the other hand, wind-tunnel experiments are performed for the reference configuration to study the overall aerodynamic characteristics. It turns out that the agreement between the numerics and experiment is very good. Depending on the chosen leading-edge contours, the numerical analyses show a different vortex formation on the SAGITTA diamond-wing configuration, which results in diverse flow topologies. Both the flow topologies and the characteristics of the aerodynamic coefficients are discussed in detail for the three analyzed configurations. Due to the 12% relative thickness airfoil, vortex formation takes place only 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.
 , “On the Vortex Formation over a Slender Wing at Large Angles of Incidence ,” AGARD Specialists’ Meeting on “High Angle of Attack Aerodynamics,” AGARD 247, Oct. 1978.
 , “Turbulente Strömungsstrukturen an Flugzeugkonfigurationen mit Vorderkantenwirbeln,” Ph.D. Dissertation, Technische Univ. München, Herbert Utz Verlag, Munich, 1997 (in German).
 , “Untersuchungen über das Aufplatzen der Wirbel an Schlanken Deltaflügeln,” Zeitschrift für Flugwissenschaften und Weltraumforschung, Vol. 13, No. 5, 1965, pp. 158–168.
 , “The Bursting of Leading–Edge Vortices. Some Observations and Disussions of the Phenomenon,” Aeronautical Research Council, Reports and Memoranda 3282, 1962.
 , “Experimental Surface Pressure Data Obtained on 65 deg Delta Wing Across Reynolds Number and Mach Number Ranges,” NASA TM-4645, 1996.
 , “Unsteady Flow Phenomena Associated with Leading-Edge Vortices,” Progress in Aerospace Sciences, Vol. 44, No. 1, 2008, pp. 48–65. doi:https://doi.org/10.1016/j.paerosci.2007.10.002
 , “Unsteady Aerodynamics of Non-Slender Delta Wings,” Progress in Aerospace Sciences, Vol. 41, No. 7, 2005, pp. 515–557. doi:https://doi.org/10.1016/j.paerosci.2005.09.002
 , “Yaw Angle Effect on Flow Structure Over the Nonslender Diamond Wing,” AIAA Journal, Vol. 48, No. 10, 2010, pp. 2457–2461. doi:https://doi.org/10.2514/1.J050380
 , “A Survey of Factors Affecting Blunt Leading-Edge Separation for Swept and Semi-Slender Wings,” 28th AIAA Applied Aerodynamics Conference, AIAA Paper 2010-4820, June–July 2010.
 , “Flow Physics Analyses of a Generic Unmanned Combat Aerial Vehicle Configuration,” Journal of Aircraft, Vol. 49, No. 6, 2012, pp. 1638–1651. doi:https://doi.org/10.2514/1.C031386
 , “Turbulent and Unsteady Flow Characteristics of Delta Wing Vortex Systems,” Aerospace Science and Technology, Vol. 24, No. 1, 2013, pp. 32–44. doi:https://doi.org/10.1016/j.ast.2012.08.007
 , “Numerical Simulation of the Peculiar Subsonic Flow-Field About the VFE-2 Delta Wing with Rounded Leading Edge,” Aerospace Science and Technology, Vol. 24, No. 1, 2013, pp. 45–55. doi:https://doi.org/10.1016/j.ast.2012.02.006
 , “Numerical Investigations on the VFE-2 65-Degree Rounded Leading Edge Delta Wing Using the Unstructured DLR TAU-Code,” Aerospace Science and Technology, Vol. 24, No. 1, 2013, pp. 56–65. doi:https://doi.org/10.1016/j.ast.2012.03.002
 , “Effects of Boundary Layer Formation on the Vortical Flow above Slender Delta Wings,” RTO AVT Specialists’ Meeting on “Enhancement of NATO Military Flight Vehicle Performance by Management of Interacting Boundary Layer Transition and Separation,” RTO-MP-AVT-111, NATO Research and Technology Organization, Prague, Oct. 2004.
 , “SAGITTA—Nationale Forschungskooperation für Fortschrittliche UAV-Technologien im Rahmen der Open Innovation Initiative von Cassidian,” 61st Deutscher Luft- und Raumfahrtkongress, Deutscher Luft- und Raumfahrtkongress 1352, Berlin, Sept. 2012.
 , “Leading-Edge Geometry Effects on the Vortex System Formation of a Diamond Wing Configuration,” 31st AIAA Applied Aerodynamics Conference, AIAA Paper 2013-3187, June 2013.
 , “Experimental Investigations on Vortex Flow Phenomena of a Diamond Wing Configuration,” 29th Congress of the International Council of the Aeronautical Sciences, International Council of the Aeronautical Sciences 4.1.1, St. Petersburg, Russia, Sept. 2014.
 , “Aerodynamic Characteristics of the SAGITTA Diamond Wing Demonstrator Configuration,” 61st Deutscher Luft- und Raumfahrtkongress, Deutscher Luft- und Raumfahrtkongress 281220, Berlin, Germany, Sept. 2012.
 , “Overview of the Hybrid RANS Code TAU,” MEGAFLOW—Numerical Flow Simulation for Aircraft Design,
Notes on Numerical Fluid Mechanics and Multidisciplinary Design, Vol. 89, Springer-Verlag, New York, 2005, pp. 81–92.
 , “The DLR TAU-Code: Recent Applications in Research and Industry,” 4th European Conference on Computational Fluid Dynamics, European Community on Computational Methods in Applied Sciences CFD 2006-619, Egmond aan Zee, The Netherlands, Sept. 2006.
 , “Comparison and Evaluation of Cell-Centered and Cell-Vertex Discretization in the Unstructured TAU-Code for Turbulent Viscous Flows,” 5th European Conference on Computational Fluid Dynamics, European Community on Computational Methods in Applied Sciences CFD 2010-1251, Lisbon, June 2010.
 , “Reynolds-Averaged Navier–Stokes Solutions for the CAWAPI F-16XL Using Different Hybrid Grids,” Journal of Aircraft, Vol. 46, No. 2, 2009, pp. 409–422. doi:https://doi.org/10.2514/1.35106
 , “Lessons Learned from Numerical Simulations of the F-16XL Aircraft at Flight Conditions,” Journal of Aircraft, Vol. 46, No. 2, 2009, pp. 423–441. doi:https://doi.org/10.2514/1.35698
 , “Prediction of the Flow Around the X-31 Aircraft Using Three Different CFD Methods,” Aerospace Science and Technology, Vol. 20, No. 1, 2012, pp. 21–37. doi:https://doi.org/10.1016/j.ast.2011.07.014
 , “Integrated Computational/Experimental Approach to Unmanned Combat Air Vehicle Stability and Control Estimation,” Journal of Aircraft, Vol. 49, No. 6, 2012, pp. 1542–1557. doi:https://doi.org/10.2514/1.C031430
 , “An Integrated Computational/Experimental Approach to X-31 Stability and Control Estimation,” Aerospace Science and Technology, Vol. 20, No. 1, 2012, pp. 2–11. doi:https://doi.org/10.1016/j.ast.2011.10.010
 , “Numerical Solutions of the Euler Equations by Finite Volume Methods Using Runge–Kutta Time-Stepping Schemes,” 14th AIAA Fluid and Plasma Dynamics Conference, AIAA Paper 1981-1259, June 1981.
 , “Lower-Upper Implicit Schemes with Multiple Grids for the Euler Equations,” AIAA Journal, Vol. 25, No. 7, 1987, pp. 929–935. doi:https://doi.org/10.2514/3.9724
 , “Multigrid Solution of the Euler Equations Using Implicit Schemes,” AIAA Journal, Vol. 24, No. 11, 1986, pp. 1737–1743. doi:https://doi.org/10.2514/3.9518
 , “One-Equation Turbulence Model for Aerodynamic Flow,” 30th AIAA Aerospace Sciences Meeting and Exhibit, AIAA Paper 1992-0439, Jan. 1992.