Unified Interpolated‐Based Scheme for Curved Boundary Treatment of the Discrete Unified Gas Kinetic Scheme

ABSTRACT This paper proposes the unified interpolated‐based scheme for curved boundary treatment of the discrete unified gas kinetic scheme (DUGKS). The construction of the proposed boundary scheme is the combination of interpolation and the straight boundary condition (i.e., bounce‐back (BB), non‐equilibrium bounce‐back (NEBB), and moment‐based scheme). To note that, this paper is the first to adopt the moment‐based boundary condition to combine with the interpolation‐based scheme for curved boundary treatment. The asymptotic analysis confirms that the proposed schemes are of first‐order accuracy. Their feasibility and accuracy are examined for different spatial grid resolutions through several numerical tests. They are robust and easy to implement. The results agree well with the analytical solution and validate the first‐order accuracy. It is found that the moment‐based scheme has better accuracy than both BB and NEBB schemes.