ENGRID: A graphical interactive code for the computation of structured grids for blocked flow domains

The underlying idea of the widely used and accepted multiblock approach for flow analysis is to subdivide a geometrical complex flow domain region into several smaller, more manageable regions, referred to as blocks. Typically there are several individual blocks in a given flow domain, each block having three computational coordinates. In the present approach the grid generation process is divided into two sub-processes; a) block decomposition, i.e., the creation of blocked flow domains and b) grid generation, i.e., the computation of structured grids in the blocks. The ENGRID code is a general purpose multi-block grid generation code for the computation of Euler or Navier-Stokes types of grids in flow domains which are already subdivided into blocks. The two required input files for ENGRID is a topology and geometry file. The topology file defines the topology of a multi-block flow domain. The topology of a blocked flow domain describes how the blocks are connected to each other. The geometry file contains the geometrical information of a multi-block flow domain. The file contains the geometrical definition of all vertices, all non-default elementary edges and all non-default elementary faces.