Chapter 6: Tandem Vane

This tutorial includes:

This tutorial teaches you how to:

  • Create a mesh involving tandem vanes using a topology template.

As you work through this tutorial, you will create a mesh for a blade set of a radial machine component that has tandem vanes. A typical blade set is shown by the black outline in the figure below.

The component has 16 blade sets, each containing one main blade and one tandem vane. Within the blade passages, the maximum diameter of the shroud is approximately 52.2 cm.

You will begin by loading the geometry from a BladeGen.inf file. You will then select a topology template and set the mesh density.

If this is the first tutorial you are working with, it is important to review Introduction to the Ansys TurboGrid Tutorials before beginning.

 

6.1. Preparing the Working Directory

  1. Create a working directory.

    Ansys TurboGrid uses a working directory as the default location for loading and saving files for a particular session or project.

  2. Download the tandem.zip file here .

  3. Unzip tandem.zip to your working directory.

    Ensure that the following tutorial input files are in your working directory:

    • BladeGen.inf

    • shroud.curve

    • hub.curve

    • profile.curve

  4. Set the working directory and start Ansys TurboGrid.

    For details, see Setting the Working Directory and Starting Ansys TurboGrid.

 

6.2. Defining the Geometry

  1. Click File > Load TurboGrid Init File.

  2. Open BladeGen.inf from the working directory.

 

6.3. Creating the Topology and Mesh

While TurboGrid can automatically generate acceptable meshes for basic turbomachinery, you may need to specify topology templates for complex blade configurations, such as tandem vanes.

Select the appropriate template as follows:

  1. In the Mesh workspace, open Topology Set.

  2. Set ATM Topology > Method to Tandem Vane Aligned High.

  3. Click Apply.

  4. Right-click Topology Set and turn off Suspend Object Updates.

The topology and 3D mesh are generated.

The error indicated for Mesh Data > Main Blade Boundary Layer Control is caused by the near-wall expansion rates. This will be resolved in the next section.

 

6.4. Setting the Mesh Density

  1. Open Mesh Data.

  2. On the Mesh Size tab, set Method to Global Size Factor.

  3. Set Size Factor to 1.35.

  4. Click Apply.

 

6.5. Saving the Mesh

Save the mesh:

  1. Click File > Save Mesh As.

  2. Ensure that Files of type is set to Ansys CFX Mesh Files.

  3. Set Export Units to cm.

  4. Set File name to tandemvane.gtm.

  5. Ensure that your working directory is set correctly.

  6. Click Save.

 

6.6. Saving the State (Optional)

If you want to revisit this mesh at a later date, save the state:

  1. Click File > Save State As.

  2. Enter an appropriate state filename.

  3. Click Save.