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Improved curved-boundary scheme for lattice Boltzmann simulation of microscale gas flow with second-order slip condition
Physical Review E ( IF 2.2 ) Pub Date : 2022-02-28 , DOI: 10.1103/physreve.105.025310
Wentao Dai 1 , Huiying Wu 1 , Zhenyu Liu 1 , Shengyuan Zhang 1
Affiliation  

An improved curved-boundary scheme with second-order velocity slip condition for multiple-relaxation-time–lattice Boltzmann (MRT-LB) simulation of microgas flow is proposed. The proposed interpolation bounce-back (IBB)–explicit counter-extrapolation (ECE) scheme adopts the IBB method to describe the curved boundary, while the ECE method is employed to predict the slip velocity on gas-solid interface. To incorporate the effect of second-order velocity slip term and the influence of boundary curvature, a slip velocity model is also derived, from which the gas slip velocity is captured by the ECE discretization method. The influence of fictitious slip velocity can be eliminated by adopting the present ECE method, and the influence of actual offset between the lattice node and the physical boundary can be well considered by the IBB method. The proposed IBB-ECE boundary scheme is then implemented with the MRT-LB model and tested by simulations of force-driven gas flow in horizontal (inclined) microchannel, gas flow around a micro-cylinder, and Couette flow between two micro-cylinders. Numerical results show that the proposed IBB-ECE scheme improves the computational accuracy of gas slip flow (0.001<Kn0.1) when compared with other boundary schemes reported in the literature, and provides a precise and easy implementing scheme for curved boundary with second-order slip condition.

中文翻译:

具有二阶滑移条件的微尺度气体流动的格子 Boltzmann 模拟改进曲线边界格式

提出了一种改进的具有二阶速度滑移条件的曲线边界格式,用于微气体流动的多重松弛时间-格子玻尔兹曼(MRT-LB)模拟。所提出的插值反弹(IBB)-显式反外推(ECE)方案采用IBB方法描述弯曲边界,而ECE方法用于预测气固界面上的滑移速度。为了结合二阶速度滑移项的影响和边界曲率的影响,还推导出了滑移速度模型,通过ECE离散化方法捕获了气体滑移速度。采用现有的ECE方法可以消除虚拟滑移速度的影响,而采用IBB方法可以很好地考虑格子节点与物理边界的实际偏移量的影响。然后使用 MRT-LB 模型实施所提出的 IBB-ECE 边界方案,并通过模拟水平(倾斜)微通道中的力驱动气体流动、微圆柱周围的气体流动和两个微圆柱之间的 Couette 流动进行测试。数值结果表明,所提出的IBB-ECE方案提高了气体滑流的计算精度(0.001<Kn0.1)与文献报道的其他边界方案相比,为具有二阶滑移条件的弯曲边界提供了一种精确且易于实现的方案。
更新日期:2022-02-28
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