An effective pseudo-potential lattice Boltzmann model with extremely large density ratio and adjustable surface tension
An effective pseudo-potential lattice Boltzmann model with extremely large density ratio and adjustable surface tension
复制标题
一种有效的具有极大密度比和可调表面张力的赝势晶格玻尔兹曼模型
DOI：
10.1063/5.0123727
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发表时间：
2022-11
影响因子：
4.6
通讯作者：
Binghai Wen
中科院分区：
文献类型：
--
作者：
Zhangrong Qin;Jianfei Zhu;Wenbo Chen;Chengsheng Li;Binghai Wen
赝势格子Boltzmann（LB）模型由于引入了介观相互作用势，可以直接描述非理想效应，避免了对相界面的跟踪或积分，因而在多相流模拟中具有广泛的应用前景。在本文中，我们开发了一个有效的赝势格子Boltzmann模型，同时实现热力学一致性，极大的密度比，和可调的表面张力。通过比例因子将网格空间与动量空间解耦，更密集的晶格节点可以更准确地描述过渡区域。高精度显式有限差分法进一步提高了相互作用力的计算精度。本模型被验证，以满足热力学即使在很低的温度下，其中的液-气密度比超过10 - 10。尽管密度比达到数万，寄生电流可以被抑制到非常低的水平（0.0007）。引入了一种修正的压力张力来调节表面张力，使其不受密度比的影响。数值模拟结果表明，在雷诺数为25 000，密度比大于10 000时，多相流模拟的数值稳定性得到了显著提高。
The pseudo-potential lattice Boltzmann (LB) model is versatile in modeling multiphase flows since the mesoscopic interaction potential enables it to directly describe the nonideal effect evading the tracking or integrating of phase interface. In this paper, we develop an effective pseudo-potential lattice Boltzmann model to simultaneously realize the thermodynamic consistency, the extremely large density ratio, and the adjustable surface tension. Decoupling the mesh space from the momentum space by a scale factor, denser lattice nodes depict the transition region more accurately. The high-precision explicit finite difference method (EFM) further enhances the calculation accuracy of interaction force. The present model is validated to satisfy thermodynamic even at very low temperature, where the liquid–gas density ratio exceeds 10 10 . The spurious current can be suppressed to a very low level (0.0007) despite the density ratio reaching tens of thousands. A modified pressure tension is introduced to tune the surface tension free from the influence of the density ratio. The numerical stability of multiphase simulations is significantly improved, and the droplet splashing is successfully reproduced at Reynolds number 25 000, while the density ratio is more than 10 000.