Quad tree grid generation using the concept of linked lists
Ansook Sul, Jang Hyuk Kwon · 2011
The grid system of CFD (Computational Fluid Dynamics) is divided into two parts: the body fitted grid system and the non-body fitted grid system. The main advantage of body fitted grid system is to impose boundary condition simply and directly while this grid system has some difficulties in generating grids around a complex body. Furthermore high dependence on users' skill of generating grids is required. The main advantages of non-body fitted grid system are to generate grids around a complex body efficiently and not to require users' dependency. This paper applies the Cartesian grids which is one of non-body fitted grids system. The Cartesian grids apply quad tree data structure and store information of cells' heredity. This data structure is efficient to make adaptive Cartesian grids and to find each cells of mother and child cells' information. Furthermore it is expected to apply solution adaptation simply for analysing the flow. We use the concept of linked lists and FORTRAN language for constructing quad tree data structure. The concept of linked lists can readily treat cells' data when process of creation and destruction of cells are repeated and also be efficient to access the cells' information. The grids generated by this process are used for solving the governing equation like a Navier-Stokes equation which applies Immersed Boundary Method or Cut-cell Method.