Comparing Mesh Types

We have already examined the velocity plot and seen that the numerical solution compares well with the experimental data. We will now compare the velocity data produced on this mesh with those produced on the Hexahedral Mesh and the Tetrahedral Mesh.

Open the Tools node.

Right-click on the Tables node and select New > File....

Locate file hex380.csv saved in the Hexahedral Mesh.

Click Open.

Do the same to import the data saved in file tet380.csv.

Open the Plots > Velocity Plot at X = 0.38 node.

Right-click on the Tabular node and select New Tabular Data Set.

Select the new tabular 2 node

In the Properties window, select hex380 for the Table property

Once again, right-click on the Tabular node and select New Tabular Data Set

Select the new tabular 3 node

In the Properties window, select tet380 for the Table property

Rename the tabular node Experimental

Rename the tabular 2 node HexMesh

Rename the tabular 3 node TetMesh.The simulation tree should appear as shown below when you done.

The node representing the internal data set cannot be renamed directly as it inherits its name from the plane section part. Therefore, rename the part instead:

Open the Derived Parts node.

Right-click on the X = 0.38 node and rename it as PolyMesh.

The plot will be easier to read if continuous lines are used for the numerical data rather than circular symbols. To achieve this:

Select the Plots > Velocity Plot at X = 0.38 > Y Types > Y Type 1 > PolyMesh > Symbol Style node.

Change the Shape property to None.

Select the Line Style node.

Change the Style property to Solid.

Select the PolyMesh node.

Enable the Sort Plot Data option in the Properties window.

The graph for the PolyMesh internal data set should now be shown as a red line. To display the HexMesh and TetMesh data sets as lines as well:

Open the Tabular node.

Within both the HexMesh and TetMesh nodes, change the Line Style and Symbol Style properties to display a solid line.

Within the Experimental node, change the Color property of the Symbol Style node to black.

There is little difference in the quality of the results obtained from the three meshes, although the result from the polyhedral mesh is slightly better than the other two in the recirculation zone. This is despite the polyhedral mesh having only 60,838 cells compared to 67,699 cells for the hexahedral mesh and 140,141 cells for the tetrahedral mesh. Furthermore, the analysis on the polyhedral mesh required only 121 iterations to reach convergence compared to 221 for the hexahedral mesh and 181 for the tetrahedral mesh. The results therefore demonstrate the ability of polyhedral meshes to produce good quality results with lower cell counts and shorter run times than other mesh types.