Disable Pre-Mesh.

 Blocking > Pre-Mesh

Redisplay Curves and Edges.

See the distribution of grid points along the edges (Figure 14: Initial Bunching).

 Blocking > Edges > Bunching

Figure 14: Initial Bunching

Display the vertex numbers.

 Blocking > Vertices > Numbers

Reduce the number of nodes along the length of the large pipe.

Blocking > Pre-Mesh Params   > Edge Params  

1. Select edge 13–34.

2. Enter 27 for Nodes and click Apply.

3. Similarly,click   (Select edge(s), select edge 21–38, enter 27 for Nodes and click Apply.

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   Note:  This is a structured grid. When the number of nodes is changed on one edge, all parallel edges will automatically have the same number of nodes. In this case, edges 41–42 and 43–44 will have the same number of nodes as 13–34 and 38–21 respectively.

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   Figure 15: Bunching After Changing the Number of Nodes

   
   
   

4. Enable Pre-Mesh and recompute the mesh.

Bias the nodes close to the wall boundaries of the large pipe.

1. Select edge 13–41, and enter 0.5 for both Spacing 1 and Spacing 2.

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   Note:  Spacing 1 refers to the node spacing at the beginning of the edge, while Spacing 2 refers to the spacing at the end of the edge. The beginning of the edge is shown by the arrow after the edge is selected.

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2. Enter 1.2 for both Ratio 1 and Ratio 2.

   Requested values for spacing and ratio are typed in the first column. Actual values are displayed in the second column. Note that due to the number of nodes, the mesh law and spacing, the requested ratios may not be attained. You may increase the number of nodes using the arrows until the ratios are close to the requested value.

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   Note:  The Mesh Law is by default set to BiGeometric. This allows the nodes to be biased towards both ends of the edge. The expansion rate from the end is a linear progression. Several other mathematical progression functions (laws) are available.

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3. Enable Copy Parameters and retain the selection of To All Parallel Edges in the Method drop-down list.

   This will ensure that the parallel edges 34–42, 38–43, and 21–44 have the same spacing.

4. Click Apply.

Bias the nodes along the length of the long pipe.

1. Select edge 21–38 and change Spacing 1 and Spacing 2 to 0.5.

   This will concentrate grid points toward the outlet and toward the small pipe.

2. Ensure that Copy Parameters is enabled and To All Parallel Edges is selected in the Method drop-down list.

   These changes will be reflected in edge 43–44 as well.

3. Click Apply.

4. An available Copy option will be used to concentrate grid points toward the inlet and toward the small pipe.

   In the Copy group box, select To Selected Edges Reversed in the Method drop-down list.

5. Click   (Select edge(s)) and select edges 13–34 and 41–42. Click the middle mouse button to accept.

6. Click Apply.

Refine the nodes along the small pipe.

1. Select edge 33–42 and enter 9 for Nodes.

2. Enter 1.0 for Spacing 1 and 0.5 for Spacing 2, respectively.

3. Ensure that Copy Parameters is enabled and select To All Parallel Edges in the Method drop-down list.

4. Click Apply.

5. Similarly, select edge 33–37, enter 9 for Nodes, and click Apply.

Disable and then enable Pre-Mesh to recompute the mesh (Figure 16: Refined Mesh).

 Blocking > Pre-Mesh

Figure 16: Refined Mesh