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How to Add Tracers in FLOW-3D Cast

Metal casting is a process where liquid metal is poured or injected into an open cavity, allowed to solidify, and ejected or broken out of the mold/die. The gate(s) are located where metal enters the cavity of the casting and are placed in the thickest regions to promote directional solidification. The number of gates depends on the desired distribution of flow into the cavity. Metal flow is difficult to trace experimentally so the use of simulation is important to ensure that the final design results in quality parts. One way to visualize how each gate contributes to the filling of the metal casting is to run a simulation with tracers placed at each gate. A high pressure die casting of a cover plate will be used to illustrate how to apply tracers and analyze them. The steps to setting up the entire simulation will not be given here, only how to implement the tracers and post-process them in FLOW-3D Cast.

  1. First the locations of the baffles (flux planes) need to be determined. The user can get these from the CAD designer or can use the probe option to determine the location and size of the baffle. The following steps will show the user how to get the location and size of the first gate. The same process can be repeated for additional gates.
    1. Ensure you are looking at the part in 2-D. For this example we will start with the x-y plane.
    2. Select the probe icon located on the right-hand side toolbar.
    3. Left-click near the location where the flux plane will be defined, a probe dialog box will open and give an accurate location in the x and y directions.
    4. Write down the x-direction. Switch the 2-D view to z-y plane. Select extents in the z-direction by selecting ends of gate. Write down the z extents. See Figure 2 for how the z extents were determined. The same procedure is used for the y extents.
Simulating flow tracers for better visualization in FLOW-3D Cast
Figure 1. Steps to locate the position of the tracer for the gate along the x-axis.

 

How to add tracers in FLOW-3D Cast
Figure 2. Finding extents in the z-direction by using the probe function.
  1. Define the baffle location and size.
    1. Select Flow menu > Special parameters > Baffles… A dialog box will open up to define the baffle flux planes and the tracers.
    2. Select New, to add a plane/tracer.
    3. Select the Tracers box to activate tracers.
    4. Select the radio button to define the axis on which the tracer plane will be placed. In this example it is x.
    5. Enter the location found in step 1c.
    6. Define the plane using the extents found in 1d and 1f. Figure 3 shows how to define the baffle/tracer.
    7. Select the Apply button.
Adding baffles to flow tracer simulations in FLOW-3D Cast
Figure 3. Shows how to add a baffle.

 

The tracers will be added as green lined planes. Figure 4 shows all the added tracers.

Arrows indicate the location of tracers or baffles in FLOW-3D Cast
Figure 4. Black arrows show location of
tracers or baffles indicated by green planes.
  1. Run the simulation.
  2. Post-process the results: The user must determine what information they want to get from the results. For example, the information important for this simulation is the distribution of the flow through each of the gates. This can be viewed by selecting combined tracers, which will display all tracers. Each tracer can be viewed independently too.
    1. Select the post-processing button.
    2. Set the parameters as shown in Figure 5.

Post-processing results for flow tracers in FLOW-3D Cast
Figure 5. Settings for post-processing results to see
all tracers and their combinations.
The maximum number of tracers available is 7, which is indicated on the color bar as the high value in Figure 5. The low and high numbers indicate the tracer number with 0 being no tracer. The tracers are labeled according to the order they were created. The user can change the high and low numbers to show those tracers and their combinations. For now we will look at all of them. In Figure 6, some colors seem to blend together. For instance tracer 2 and 3 are both a shade green and look very similar. To change the color scale select View > Colors > Edit color scale. Options are available to add or delete colors. When using more than 4 tracers, the combinations of the tracers become more difficult to determine. When this is the case, the user can reduce the number of tracers to better visualize by changing the high and low values.
Visualizing flow tracers and their combinations in FLOW-3D Cast
Figure 6. All 7 tracers and their combinations.


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