Modelling , Analysis and Simulation Application of a Chimera Technique to the Computation of Subsonic and Transonic Bi - Airfoil Flows

CWI's research has a theme-oriented structure and is grouped into four clusters. Listed below are the names of the clusters and in parentheses their acronyms. ABSTRACT This paper describes the application of a composite overset-grid technique to flow computations around a two-dimensional bi-plane. The flow is described by the steady, 2D, compressible Euler equations of gas dynamics. The discretization method used is a central finite-difference method with artificial dissipation. The overset-grid technique is of chimera-type and the bi-plane a bi-NACA0012 airfoil. ABSTRACT This paper describes the application of a composite overset-grid technique to flow computations around a two-dimensional bi-plane. The flow is described by the steady, 2D, compressible Euler equations of gas dynamics. The discretization method used is a central finite-difference method with artificial dissipation. The overset-grid technique is of chimera-type and the bi-plane a bi-NACA0012 airfoil. 1. Introduction Composite overset-grid techniques enable the generation of structured grids around complicated ge-ometries and are particularly useful when one needs to rotate or translate one piece of geometry with respect to another. The first requirement to be fulfilled by an overset-grid technique is that the computational domain is entirely covered by grids. The overset-grid technique to be considered here is of chimera type [2, 8]. Overset-grid techniques give us the opportunity to adaptively refine a single subgrid without changing the other subgrids [6], and they can be combined with multigrid methods [4]. A chimera technique requires two specific additional algorithms: (i) an algorithm for generating the separate grids and for cutting holes in the grid parts which are overlapped, and (ii) an algorithm for interpolating solutions and possibly righthand sides between the various grids. As mentioned, the test geometry to be considered is a bi-NACA0012 airfoil. For a precise definition of this geometry, we refer to [3]. The specific test cases to be considered are: (i) M ∞ = 0.5, α = 0, (ii) M ∞ = 0.75, α = 0 and (iii) M ∞ = 0.55, α = 6 o. The first and the last test case are taken from