Drag and lift forces are very important in engineering applications and, therefore, many research projects have been conducted to control these forces. In this paper, the effects of an upstream porous plate on the hydrodynamic forces over a square cylinder are investigated using lattice Boltzmann method. The main idea is to separate the obstacle from the upstream flow by adding such a porous plate, since the magnitudes of the drag and lift forces have a direct relationship with the phenomena of vortices shedding from the obstacle. In order to have a better insight into the problem, streamlines, vorticity contours and lift and drag coefficients are presented for different case studies. Results proved that the porous plate can reduce the drag and lift coefficients. Furthermore, increasing the height and the gap spacing (i.e., the surface-to-surface distance between the porous plate and the obstacle) could significantly affect the flow field characteristics and the forces acting on the obstacle.

拖拉力在工程应用中非常重要，因此，已经进行了许多研究项目来控制这些力。在本文中，使用格子Boltzmann方法研究了上游多孔板对方形圆柱体上流体动力的影响。主要思想是通过添加这种多孔板来将障碍物与上游流体分离，因为阻力和升力的大小与涡流从障碍物脱落的现象有直接关系。为了更好地了解问题，针对不同的案例研究提出了流线，涡度轮廓以及升力和阻力系数。结果证明，多孔板可以减小阻力和升力系数。此外，增加高度和间隙间距（即