Assessment of d'Alembert's paradox in panel methods by tangency correction

The aim of this study is to introduce a correction for panel methods in order to obtain correct viscous pressure drag of a steadily moving body in a viscous fluid. The boundary tangency correction implemented through a surface normal deflection term was added into a panel method implementation. A quadratic programming algorithm was used to solve inverse problems in order to prove the correction well-posedness and to obtain accurate surface pressure distribution, based on the experimental data. The experimental surface pressure distributions were collected from the literature for circular cylinders in steady uniform flow. The solutions of normal deflections were validated and the direct connection of the introduced correction to the boundary layer displacement thickness was found, which can simplify the process of viscous-inviscid coupling between integral boundary layer and panel methods.