A dynamic boundary model for implementation of boundary conditions in lattice-Boltzmann method

Methodology of implementation of the no-slip boundary condition in the lattice-Boltzmann method affects overall accuracy of the numerical solutions as well as the stability of the solution procedure. We propose a new algorithm, i.e., the method of using a dynamic equation for establishing no-slip boundary conditions on walls. The distribution functions on the wall along each of the links across the physical boundary are assumed to be composed of equilibrium and non-equilibrium parts which inherit the idea of Guo's extrapolation method (2002). In the proposed algorithm, we employed a dynamic equation to correct the velocity error occurring on the physical boundary. Numerical results show that the dynamic boundary model is featured with improved accuracy and simplicity. The proposed method is postulated to be useful especially in the study on microfluidic mixing.