| We investigate obstructed flow in a quantum superfluid. Utilizing a flattened 2D Bose-Einstein condensate whose dynamics are prescribed by the Gross-Pitaevskii equation in a co-moving reference frame, we show that the superfluid Reynolds number characterizes the wake patterns behind the obstacle. Furthermore, by combining a fringe damping region and a boundary condition derived to emulate far-field conditions, we develop stable absorbing boundary conditions for a 2D BEC that allow simulations in the supersonic flow regime. The absorbing boundary conditions are tested for a wide range of situations whereby multiple vortices and radiation waves are succesfully absorbed at the boundary. Additionally, these absorbing boundary conditions, are very straightforward to implement. |
