Abstract:

Lattice Boltzmann method was used for the numerical simulation of a flow past an elliptic cylinder. The drag of a flow around elliptic cylinders with various shapes was investigated. Firstly, the classical flow past a circular cylinder was simulated numerically. The drag coffecient of our simulation is consistent with those of other numerically results. Secondly, the flow past an elliptic cylinder with different shapes was computed by fixing the vertical semi axis length and varying the horizontal semi axis length. The numerical interpolation was used for boundary treatment, and momentum exchange method was employed to evaluate the force on the boundary. The streamlines, vorticity contours and drag were obtained for the flows past the cylinders with different shapes. Finally, we explained the drag mechanism by analyzing the variation of streamlines and vorticity contours.

Key words: lattice Boltzmann, drag reduction, drag coefficient