Abstract: A twodimensional ninevelocity Lattice Boltzmann model was employed to simulate the flow past a rectangular elongated cylinder numerically. The secondorder interpolation scheme was used for the boundary treatment. The Strouhal number, the drag coefficient and lift coefficient were calculated. The streamlines and the vorticity contours were presented. Under varying the length/width ratio of the rectangular, and keeping the inlet velocity to be parallel to the length side of the rectangular cylinder, numerical results show that the Strouhal number varies linearly with the length/width ratio.

Key words: Lattice Boltzmann method, Strouhal number, rectangular elongated cylinder, streamline, vorticity contour