Immersed Boundary-Lattice Boltzmann Method Using Two Relaxation Times
Immersed Boundary-Lattice Boltzmann Method Using Two Relaxation Times
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DOI：
10.1260/1757-482x.4.2.193
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发表时间：
2012-06
期刊：
影响因子：
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通讯作者：
K. Hayashi;Roberto Rojas;Takeshi Seta;A. Tomiyama
中科院分区：
文献类型：
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作者：
K. Hayashi;Roberto Rojas;Takeshi Seta;A. Tomiyama
提出了一种基于双松弛时间模型的浸没边界格子Boltzmann方法(IB-LBM)。格子Boltzmann方程中的碰撞算符用两个弛豫时间来模拟。其中一个用于设置流体粘度，另一个用于数值稳定性和精度。对于浸没边界的处理，采用了直接强迫方法。为了精确满足浸没边界上的边界条件，还采用了多重直接强迫方法。为了验证所提方法的有效性，对静止圆柱和旋转圆柱之间的圆形Couette流动进行了数值模拟。通过对圆形和球形下落粒子的模拟，验证了该方法的有效性。还考察了直接强迫项和光滑Delta函数的函数形式的影响，这些函数将流体速度内插到浸没边界，并将强迫项分配到固定的欧拉网格点。得出了以下结论：(1)该系统具有较强的可控性。
An immersed boundary-lattice Boltzmann method (IB-LBM) using a two-relaxation time model (TRT) is proposed. The collision operator in the lattice Boltzmann equation is modeled using two relaxation times. One of them is used to set the fluid viscosity and the other is for numerical stability and accuracy. Adirect-forcing method is utilized for treatment of immersed boundary. A multi-direct forcing method is also implemented to precisely satisfy the boundary conditions at the immersed boundary. Circular Couette flows between a stationary cylinder and a rotating cylinder are simulated for validation of the proposed method. The method is also validated through simulations of circular and spherical falling particles. Effects of the functional forms of the direct-forcing term and the smoothed-delta function, which interpolates the fluid velocity to the immersed boundary and distributes the forcing term to fixed Eulerian grid points, are also examined. As a result, the following conclusions are obtained: (1) the...