This paper details immersed boundary method (IBM) to facilitate numerical investigation of the laminar forced fluid flow over a forward-backward facing step through a 2D channel by treating step as an immersed boundary (IB). The present numerical method is based on a finite volume approach on a staggered grid together with a fractional step method. When an IB (step) is present, both momentum forcing and mass source terms are applied on the body surface to satisfy the no-slip boundary condition on the immersed boundary and to satisfy the continuity for the mesh containing the immersed boundary respectively. In the IBM, the necessity of an accurate interpolation scheme satisfying the no-slip condition on the immersed boundary is important because the grid lines generally do not coincide with the immersed boundary. Results are presented with respect to Reynolds numbers for different sizes of the step.
展开▼
