TY - CHAP A1 - Klein, Robert A1 - Stollberg, Christian A1 - Markowski, Jens A1 - Willscher, S. A1 - Ay, Peter ED - Önal, Güven T1 - Biodissolution for recovery of precious metals from electronic scrap T2 - Proceedings of the XXIII International Mineral Processing Congress, Istanbul, Turkey 3-8 September 2006, Vol. 2 KW - biodissolution Y1 - 2006 SN - 975-7946-29-X SP - 1557 EP - 1560 PB - Promed Advertising Agency CY - Istanbul ER - TY - GEN A1 - Klein, Marten A1 - Kessler, Robert William A1 - Schmidt, Heiko T1 - On the influence of a wavy leading edge on the aerodynamic drag of a wing: A numerical parameter study T2 - STAB Jahresbericht 2023 KW - airfoil aerodynamics KW - passive flow control KW - CFD (RANS, LES) KW - wavy leading edge Y1 - 2023 UR - https://www.dlr.de/as/Portaldata/5/Resources/dokumente/veranstaltungen/stab_workshop/Jahresbericht2023.pdf UR - https://www.dlr.de/as/desktopdefault.aspx/tabid-128/268_read-1678/ VL - 21/2023 SP - 110 EP - 111 PB - Deutsche Strömungsmechanische Arbeitsgemeinschaft (STAB) CY - Göttingen, Germany ER - TY - GEN A1 - Klein, Marten A1 - Kessler, Robert William A1 - Schmidt, Heiko T1 - Numerical investigation of drag reduction effects on a track bicycle fork using wings with a wavy leading edge T2 - Proceedings in Applied Mathematics and Mechanics N2 - Reynolds‐averaged Navier–Stokes (RANS) and large‐eddy simulations (LES) of the flow around wings with a wavy leading edge (WLE) are conducted in order to assess the capabilities of a passive flow control strategy for drag reduction. The intended application is indoor track cycling with controlled flow conditions. A section of a single fork rod is investigated in order to make the numerical simulations feasible. The present study reveals that net drag reduction is possible by a nonsinusoidal modification of the leading edge of the wing. However, the drag reduction effect remains limited to a few percent. While RANS and LES yield the same drag coefficient for a reference case, RANS underestimates the drag reduction effect for a longer wing and the WLE cases, but exhibits otherwise a qualitatively similar trend as the LES. With the aid of RANS, an optimal geometry is obtained defined by the wavelength‐to‐chord length ratio of and the amplitude‐to‐chord length ratio of . Corresponding LES results give an indication of the origin of drag reduction by a hampered vortex shedding. The generation of smaller and more streamwise oriented vortical flow structures at the trailing edge and behind the WLE wing is correlated with significantly reduced lift fluctuations and drag reduction. KW - sports aerodynamics KW - passive flow control KW - aerodynamic drag KW - drag reduction KW - computational fluid dynamics KW - turbulence modeling Y1 - 2024 U6 - https://doi.org/10.1002/pamm.202400178 SN - 1617-7061 VL - 24 SP - 1 EP - 14 PB - Wiley ER -