The stagnation phenomena of electrohydrodynamic waves in a channel

This paper investigates steady two-dimensional periodic electrohydrodynamic waves with constant vorticity in an infinite channel, where the potential difference between two electrodes reaches a critical value. We demonstrate that when the vorticity is sufficiently large, the rotational motion of fluid particles becomes dominant, reducing the local velocity to zero and resulting in stagnation phenomena. This process enables particle separation or impurity removal. Furthermore, the study reveals that the stagnation occurs beneath the free surface.