The CFD Process

1. The CAD Model

It all starts with geometry.

If you built the model in a CAD system, it probably contains solid parts. To use it with Autodesk® CFD, it needs one or more fluid parts. There are several ways to create a fluid part:

  1. Create it in CAD.

    cad geometry

  2. To make the volume water tight, build volumes that cap the openings

    water tight geompetry

  3. Use the Fluid Volume tool in Autodesk® SimStudio Tools.

    fluid tool

  4. Use the Void Fill tool in Autodesk® CFD.

    void tool

Launch the model either directly from the CAD system or by opening the model file in Autodesk® CFD.

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2. Enter What You Know

In this step, you describe the physical characteristics of the system.

A. Materials

Setup > Setup Tasks > Materials.

materials icon

Define what flows through the device--air, water, or whatever liquid--as well as the solid parts.

materials

To learn more about Materials...

B. Boundary Conditions

Setup > Setup Tasks > Boundary Conditions.

boundary conditions icon

Describe the flow at the openings and heat transfer wherever heat enters or leaves the system.

boundary conditions

To learn more about Boundary Conditions...

C. Mesh Sizing

Setup > Setup Tasks > Mesh Sizing.

mesh sizing icon

The mesh is how we convert the geometry model into a simulation model.

The process is almost entirely automatic. Simply click this button:

autosize icon

meshed part

To learn more about Meshing...

To learn more about Motion...

3. Run the Simulation

Setup > Simulation > Solve.

solve icon

After you have described the model, you are ready to solve.

Autodesk® CFD uses an iterative calculation process. This means that the solver computes a solution in many small steps (iterations). With every step, the solution evolves. After some number of iterations, the solution does not change anymore, and is considered converged.

run solve

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4. Learn what you didn't know (visualize the results)

Results > Result Tasks.

results tools

In this step, you learn how the flow and heat move within your model. Autodesk® CFD has some great tools for visualizing and extracting results.

The type of result you need largely depends on the type of application:

Valves and other flow control devices

Flow control simulations usually show how the fluid flows through the device as well as either the pressure drop or the flow rate.

example result

To practice with a flow control model, click here.

Electronics Cooling

Electronic cooling simulations typically show component temperatures and how cooling air flows through the enclosure.

ecooling result

To practice with an electronics cooling model, click here.

AEC

AEC simulations often show how the ventilation air moves in relation to the occupant, and if the occupant is comfortable.

aec result

To practice with an AEC model, click here.

5. Iterate and Compare

A single scenario is just the first step. In many cases, you may want to try several design alternatives.

design alternatives

Autodesk® CFD makes it easy to transfer settings from one model to another and run variations in the same design study.

When finished, you can compare the results in the Decision Center.

decision center icon

The Decision Center provides several ways to compare simulation results from multiple simulations:

decision center

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