Droplet impact on flat surfaces with heterogeneity is expected to trigger unusual impact dynamics, such as anisotropic spreading and directional rebounding, which in turn could be utilized in the control of droplet motion in many industrial processes. The present work illustrates a numerical study on droplet impact on a flat superhydrophobic substrate coated with a heterogeneous rectangle area, the influence of different positions and wettability of this heterogeneous area on the impact dynamics is investigated. The simulation results show the wettability of the heterogeneous area can impose significant influence on the spreading, retracting, and bouncing processes, especially when the heterogeneous area is located on a site other than the initial contact point, the bouncing of droplet is more likely to happen, and the contact time also becomes shorter. The clear pictures and analysis of the impact dynamics could advance the knowledge of how to control droplet motion by surface coatings.

液滴对具有异质性的平坦表面的撞击预计会触发不寻常的冲击动力学，例如各向异性扩散和定向反弹，这反过来又可用于控制许多工业过程中的液滴运动。目前的工作说明了液滴对涂有异质矩形区域的平坦超疏水基底的影响的数值研究，研究了该异质区域的不同位置和润湿性对撞击动力学的影响。仿真结果表明，异质区域的润湿性对扩散、回缩和弹跳过程产生显着影响，尤其是当异质区域位于初始接触点以外的位置时，更容易发生液滴弹跳, 而且接触时间也变短了。撞击动力学的清晰图片和分析可以提高有关如何通过表面涂层控制液滴运动的知识。