Gambit -- MODELING A MIXING ELBOW (2-D)

http://www.cadfamily.com/a/CAE_FEA_CFD/Gambit/Gambit----MODELING-A-MIXING-ELBOW--2-D-_7021.html

In this tutorial, you will build a 2-D mesh using a “bottom-up” approach (in contrast to

the “top-down” approach used in Tutorial 1). The “bottom-up” approach means that you

will first create some vertices, connect the vertices to create edges, and connect the edges

to make faces (in 3-D, you would stitch the faces together to create volumes). While this

process by its very nature requires more steps, the result is, just as in Tutorial 1, a valid

geometry that can be used to generate the mesh.

The mesh created in this tutorial is intended for use in FLUENT 4, so it must be a single

block, structured mesh. However, this mesh can also be used in any of the other Fluent

solvers. This type of mesh is sometimes called a mapped mesh, because each grid point

has a unique I, J, K index. In order to meet this criterion, certain additional steps must be

performed in GAMBIT and are illustrated in this tutorial. After creating the straight edges

and arcs that comprise the geometry, you will create two faces: one for the main flow passage (the elbow) and one for the smaller inlet duct. The mesh is generated for the larger

face using the Map scheme; this requires that the number of grid nodes be equal on opposite edges of the face. You will force GAMBIT to use the Map scheme to mesh the smaller

face as well.