Numerical and Experimental Analysis of Uniform Blowing on a Wing
Georg Fahland, Davide Gatti, Alexander Stroh, Bettina Frohnapfel
Turbulent flows are the most common type of everyday scenarios. Their interaction with bodies generates resistance - drag - which in most cases is undesirable in terms of energy efficiency. At ISTM multiple projects exist to reduce this drag by influencing the properties of the turbulent flows, in particular the turbulent boundary layers. The Project "Numerical and Experimental Analsis of Uniform Blowing on a Wing" aims at putting a scheme of active flow control to a realistic use case. While it is invaluable to understand the physics in the boundary layer in detail it is also crucial to identify which of the low-scale properties has the most significant influence on the macroscopic performance changes by the flow control.
The project evolved from a cooperation with KTH in Stockholm with a joined LES simulation effort to transfer the flow control scheme from a canonical case to the practical use case of a wing (DOI: https://doi.org/10.1007/s10494-020-00135-z). In a next step an extensive numerical analysis was performed to identify some major trends for an application (DOI: https://doi.org/10.2514/1.J060211). With this knowledge first thoughts aimed on the question of what to expect when taking such idealized sitation to an experimental implementaion. This included the means of measurement equiptment und subsequent findings about general effects an implementation has on the performance evaluation (DOI: https://doi.org/10.13009/EUCASS2022-6123).
In parallel to the numerical and theoretical investigations the large ISTM wind-tunnel was remodelled. In addition to other experimental campaigns a testrig was designed to test flow control devices in airfoil models. This testrig performance was evaluated with an exisiting airfoil model from TU-Braunschweig (HGR-01 airfoil, e.g. DOI: https://doi.org/10.1007/978-3-319-03158-3).
As a first conculsion of the present project an investigation is planned using a newly built model with a uniform blowing flow control device which was chosen based on the numerical investigations with a focus on strong flow control effect in order to achieve significant measurement results.