The absorption of waves in a circular wave basin using segment-type wave makers is challenging due to the curvature, which may generate undesirable imperfections in long-crested regular wave fields close to the absorbing side of the FloWave circular wave tank with a diameter of 25 m and a water depth of 2 m. A velocity component perpendicular to the wave direction could be found numerically and experimentally, which is a key tool to understand and optimise the active wave absorption in a circular wave basin. Conducting long-crested regular wave simulation using the SPH model based on Kanehira et al. (2019), the location of the hot-spots (construc-tive and destructive interference locations of waves) could be identified in the vicinity of absorption paddles as well as velocity components perpendicular to wave propagation direction, which are the potential cause of or caused by the hot-spots. Specific experimental investigations were conducted based on numerical results to validate the numerical model based on free surface elevation and local velocities. It could be shown that the location and strength of the hot-spots vary with wave frequencies and steepnesses as well as the connection between hot-spots and the velocity components perpendicular to wave direction. This combined approach has a high potential to provide insight into the absorption mechanism in a circular basin and helps to further improve the wave conditions in future.