Sciencefile: March 2010

This tutorial describes how to create the geometry for a mixing elbow and then generate a mesh in GAMBIT. The mixing elbow configuration is encountered in piping systems in power plants and process industries. It is often important to predict the flow field and temperature field in the neighborhood of the mixing region in order to properly design the location of inlet pipes. The problem to be considered is shown schematically in Figure above. A cold fluid enters through the large pipe and a warmer fluid enters through the small pipe. The two fluids mix in the elbow.

This tutorial introducing how to build a 2-D mesh using a “bottom-up” approach (in contrast to the “top-down” approach used in Tutorial 1 see TG01.PDF).
The “bottom-up” approach means that first things to do is creating 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.

In this tutorial you will learn how to:
• Create vertices using a grid system
• Create arcs by selecting the center of curvature and the endpoints of the arc
• Create straight edges between vertices
• Split an arc using a vertex point
• Create faces from edges
• Specify the distribution of nodes on an edge
• Create structured meshes on faces
• Set boundary types
• Prepare the mesh to be read into FLUENT
• Export a mesh

Several other features are also demonstrated in this tutorial:
• Using a background grid and “snap-to-grid” to quickly create a set of vertices.
• Using “pick lists” as an alternative to mouse clicks for picking entities .
• Specifying a non-uniform distribution of nodes on an edge.
• Setting boundary types.
• Exporting a mesh for a particular Fluent solver (FLUENT 4 in this case).

Related Posts :
- Tutorial : FLUENT - SIMULATING A MIXING ELBOW (2D)

DOWNLOAD TUTORIAL :
TG02.PDF