Abstract
The purpose of this paper is to solve a problem of incompressible flow in a domain which includes an internal boundary on which a Dirichlet boundary condition is imposed. We use the characteristic Galerkin scheme using B-spline basis functions based on the mixed formulation for computing incompressible flow. We employ the Lagrange multiplier method on a treatment of the internal boundary, and integrate with the Nitsche's method to overcome instability which may occur on failure of the LBBK condition. In order to confirm effectivity of the present scheme, we perform the flow around a circular cylinder.
