Manifold Setup Tutorial

Overview

In this air distribution manifold, air enters through a single port and is distributed across three outlet ports.

This tutorial is divided into two sections. In this first section, we will launch from CAD, set up the simulation model, and run it in Autodesk Simulation CFD. In the Manifold Results Tutorial, we continue the process to visualize and compare results from multiple design iterations.

This tutorial discusses the following key topics:

• Incompressible flow
• Right-click menus
• Quick Edit dialogs
• How to pre-define Summary Planes

Prerequisites

Autodesk Simulation CFD must be installed and licensed on your computer.

Manifold Geometry

The geometry consists of an inlet tube, three outlet tubes, and a distribution chamber:

The flow is distributed across the three outlet tubes. In the second design of this study, we are going to remove the middle outlet tube, and compare the resultant flow distribution with the original design.

Open the manifold assembly in your CAD system from the appropriate folder.

The geometry files are located in Program Data\Autodesk\Simulation CFD 2013\Examples\CAD\manifold.
 

CAD is one of the following CAD systems:

Inventor
Fusion
UGNX (part in UGNX)
ProEngineer (use Granite Launch Configuration)
Solid Edge
CoCreate
SpaceClaim
SolidWorks
ACIS
Parasolid
 

To Launch from CAD

If launching from Autodesk® Inventor, Pro/Engineer, or SolidWorks, select the option to launch the Active model. To create a new design study in the Design Study Manager:

1. Specify a name in the Study name field. The default name is the name of the top level assembly or the part.
2. Optionally, change the names for the Design and Scenario.
3. The default location of the study is the same path as the CAD model.
4. Click Launch.
    

Autodesk® Simulation CFD starts, and the Design Study is created.

To Launch from a Parasolid or Acis File

1. Start Autodesk® Simulation CFD from the Desktop.
2. Click New from the Get Started tab.
3. In the New Design Study dialog, click Browse, and select the Parasolid or Acis file.
4. Enter a name for the new Design Study in the Design study name field.
5. Click Create new design study.
    

Analysis Units

If launching from Autodesk® Inventor, Pro/Engineer, SolidWorks, or SpaceClaim, the model units for this example are set automatically to mm. No further steps are necessary for length unit assignment.

If launching from the other CAD tools or from the Desktop, change the length units to mm by right clicking on the Geometry branch of the Design Study Bar. On the Change Units dialog, leave Change Units checked, and click OK.

Assign Air to All Parts

We begin by assigning a material to all parts in the model. In the next several steps, we may change some of the material assignments. This step is a convenient way to ensure that all parts are assigned a material before starting the analysis.

• On the Design Study Bar, expand the Material branch.
• Right click on Unassigned, and click Edit...
• Select Air from the Name list, and click Apply.
   

Assign Velocity = 3000 mm/s to inlet

• Click Boundary Conditions from the Setup tab.
• Select the inlet.

• Click Edit from the Boundary Conditions context panel.
• On the Boundary Conditions quick edit dialog make the following settings:
  • Type = Velocity
  • Units = mm/s
  • Velocity Magnitude = 3000
  • Click Apply.

Assign Pressure = 0 Pa to Outlets

• Select the three outlets. (You will likely have to rotate the model):

• Click Edit from the Boundary Conditions context panel.
• On the Boundary Conditions quick edit dialog make the following settings:
  • Type = Pressure
  • Units = Pa
  • Pressure = 0
  • Click Apply.
     

Pre-Define Summary Planes at the Outlets

• Expand the Pressure boundary conditions under the Boundary Conditions branch of the Design Study bar.
• Right click on each surface branch, and click Create summary item.
   

Assign Mesh Sizes Automatically

• Click Mesh Sizing from the Setup tab.
• Click Autosize on the Automatic Sizing context panel.

Solve

•  Click Solve from the Setup tab.

• Make the following settings on the Solve dialog:

  • Click the Physics tab.

  • Flow = On

  • Click the Control tab.

  • Iterations to run = 100

  • Click Solve to start the analysis.
     

Next Steps...

Now that you have set up and run the first design iteration, please proceed to the next Manifold tutorial to create a second design iteration, review your results, and compare the effect of the design change on the performance of the manifold.