Simulating Airfoils at Ultra-Low Reynolds Numbers Using Panel Methods

In recent years, airfoils operating at ultra-low Reynolds numbers have garnered substantial interest, primarily due to advancements in Micro Air Vehicles rotorcraft technologies. In this study, we utilized potential flow panel methods to assess their fidelity when contrasted with physical experiments. Our findings show that the implementation of panel methods is only effective when the fluid flow remains attached, or reattaches at some juncture, to the boundary layer of the airfoil wing cross-section on the vehicle. We specifically selected these geometries to investigate the underlying physics and to analyze the impact of airfoil thickness and shape on the lift and drag coefficients. Ultimately, our study reveals that the XFOIL Software can provide precise and accurate predictions of physical quantities, given that its methodological assumptions are considered.