Determination of the Critical Cross Flow N-factor for the Low-Speed Wind Tunnel Braunschweig (DNW-NWB)

摘要: In order to determine the critical cross flow N-factor for DNW-NWB wind tunnel, transition experiments are conducted on a 3D-wing model. Infrared thermography is used detect spanwise line at various angles of attack and Reynolds numbers. The obtained lines then prescribed in RANS simulations experiment. Calculated boundary layer data laminar regions serves directly as input subsequent analysis stability. Employing local linear stability analysis, N-factors attained location each inviscid streamline. A 2-N-factor method individual treatment Tollmien-Schlichting instability. From broad variety observed scenarios, dominated cases filtered. Those calculate an uncertainty weighted mean value NWB facility. results show NCFcrit be range 7.4–9.3. Remaining scatter noticeable dependency surface side model likely related methodological shortcomings eN method.