A viscous effect of wave attractor in geometry with underwater peak

The influence of the viscosity on a wave attractor flow has been previously studied, particularly in relation to the widening of the hydrodynamical structures. In this work, we simulate an attractor flow with a peculiar bottom shape that includes an underwater hill. During the simulation, we discovered a side structure appearing beyond the wave attractor. We determined that the appearance of this structure is connected to viscosity. In this article, we consider the behavior of this newly found structure. Additionally, we discuss the challenges of energy accumulation and the estimation of the Reynolds number, which is a non-trivial problem in the context of wave attractor flows.