Chen Li, Yu Yang, Hou Guoxiang
School of Naval Architecture and Ocean Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 May;87(5):053306. doi: 10.1103/PhysRevE.87.053306. Epub 2013 May 31.
A sharp-interface immersed boundary lattice Boltzmann method (IBLBM) is developed to reduce spurious-pressure oscillations in moving boundary problems. We adopt a cut-cell-based method, i.e., the partially saturated computational cell method, because the primary cause of spurious-pressure oscillations is the failure to obey the geometric conservation law near the boundary in the sharp-interface IBLBM. We modify a sharp-interface IBLBM (ghost fluid method) to fit the cut-cell approach. This boundary condition can guarantee the Dirichlet and Neumann boundary conditions for velocity and pressure. Some simulations are shown to test the validity of the method, including a circular cylinder with motions that are at rest, moving, oscillatory, and neutrally buoyant. The results illustrate that the method reduces effectively spurious pressure and can simulate moving boundary problems, especially when pressure field accuracy is a key concern.
为减少移动边界问题中的虚假压力振荡，开发了一种尖锐界面浸入边界格子玻尔兹曼方法（IBLBM）。我们采用基于切割单元的方法，即部分饱和计算单元法，因为在尖锐界面IBLBM中，虚假压力振荡的主要原因是边界附近不遵守几何守恒定律。我们修改了一种尖锐界面IBLBM（幽灵流体法）以适应切割单元方法。这种边界条件可以保证速度和压力的狄利克雷和诺伊曼边界条件。给出了一些模拟来测试该方法的有效性，包括一个静止、移动、振荡和中性浮力运动的圆柱体。结果表明，该方法有效地降低了虚假压力，能够模拟移动边界问题，特别是在压力场精度是关键问题时。
