A high-order immersed interface method for simulating unsteady incompressible flows on irregular domains
Immersed boundary methods and immersed interface methods are becoming increasingly popular for the computation of unsteady flows around complex geometries using a Cartesian grid. While good results, both qualitative and quantitative, have been obtained, most of the methods rely on low-order corrections to account for the immersed boundary. The objective of the present work is to present, as an alternative, a high-order modified immersed interface method for the 2D, unsteady, incompressible NavierStokes equations in stream functionvorticity formulation. The method employs an explicit fourth-order RungeKutta time integration scheme, fourth-order compact finite-differences for computation of spatial derivatives, and a nine-point, fourth-order compact discretization of the Poisson equation for computation of the stream function. Corrections to the finite difference schemes are used to maintain high formal accuracy at the immersed boundary, as confirmed by analytical tests. To validate the method in its application to incompressible flows, several physically relevant test cases are computed, including uniform flow past a circular cylinder and TollmienSchlichting waves in a boundary layer.
immersed interface immersed boundary finite difference methods incompressible viscous fluids cartesian grid method