A Study on the Numerical Stability and Accuracy of Lattice Boltzmann Method with Non-equilibrium first order extrapolation boundary condition

비평형 1 차 외삽 경계조건을 이용한 격자 볼츠만 법의 수치적 안정성 및 정확도에 관한 연구

Non-equilibrium first order extrapolation boundary condition proposed by Guo et $al.^{(9)}$ proposed has a good application for complex geometries, a second order accuracy and a treatment on non-slip wall boundary condition easily. However it has a lack of the numerical stability from high Reynolds number. Guo et $al.^{(9)}$ substituted the density value of adjacent nodes for the density of boundary nodes. This procedure causes the numerical instability on the boundary. In this paper, we derived a procedure of density extrapolation and compared to previous results.