Bénard–von Kármán vortex street in a dipolar Bose–Einstein condensate

The Bénard–von Kármán vortex street in dipolar Bose–Einstein Condensate trapped by a harmonic potential is investigated numerically. The results show that when the velocity of the obstacle potential increases to a certain value and for a suitable potential width, the vortex pairs released from the moving obstacle potential alternately will form a periodic anti-symmetric double-row in dipolar BEC, and forming a Bénard–von Kármán vortex street. The influence of the dipole interaction strength, the width and the velocity of the obstacle potential on the vortex structure produced in the wake is also studied, and the structure of the phase diagram is obtained. The drag force on the obstacles potential is calculated, and the mechanical mechanism of vortex pair is analyzed.