Chapter 14	MULTIPLE CYLINDERS
	STAR Set-Up in es-ice

•Click CP Transform to transform the cell couples created into one-to-one connections between cell faces, as shown in Figure 14-13

After CP Transform

Before CP Transform

Figure 14-13 Before and after CP Transform

Finally, assemble the cylinders and manifolds to create the assembled, trimmed template.

•Check that the Set uses toggle button is selected, which ensures that equivalent cylinders and ports share initial and boundary conditions

•Click Finish to assemble the overall model

Combustion

Open the Combustion view of the Star controls panel (see Figure 14-14) to check that the default settings are acceptable for this case. Remember that you are employing the Wiebe heat release correlation to reduce processing times (as the case contains a large numbers of cells) but this will affect the solution quality as there is no reaction between scalars and the flame propagation cannot be tracked.

Figure 14-14 Multiple cylinder Star Controls > Combustion panel

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Initialization

In the Initialization view of the Star controls panel, specify initial conditions for all engine components.

For the cylinder component of Cylinder 1 (see Figure 14-15), set the following conditions:

•Check that Cylinder of Cylinder 1 is selected from the domain drop-down menus at the top of the panel

•Set the Absolute pressure to Table in image. Typically, pressure data would be imported from a file but, for the sake of convenience, the data for this case have already been saved as an image in the model file.

•Check that the cylinder-3600.dat image is selected and that the column number is set to 2

•Set the pressure units to bar

•Set the Temperature to Table in image

•Check that the cylinder-3600.dat image is selected and that the column number is set to 3

•Check that the temperature units are K

Figure 14-15 Multiple cylinder Star Controls > Initialization panel for Cylinder

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Chapter 14	MULTIPLE CYLINDERS
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For Port 1 of Cylinder 1 (see Figure 14-16), specify the following initial conditions:

•Set the domain to Port 1 of Cylinder 1 from the drop-down menus at the top

•Ensure that Valve function is set to Intake

Figure 14-16 Multiple cylinder Star Controls > Initialization panel for Port1

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For Port 2 of Cylinder 1 (see Figure 14-17), specify the following initial conditions:

•Set the domain to Port 2 of Cylinder 1 from the drop-down menus at the top

•Set the Valve function to Exhaust

Figure 14-17 Multiple cylinder Star Controls > Initialization panel for Port 2

As you have already selected the Set uses toggle button in the Assembly view of the Star controls panel, only Port 1 and Port 2 of Cylinder 1 have been fully defined. The remaining intake ports will automatically use the initial conditions defined for Port 1 and the exhaust ports will use the initial conditions defined for Port 2. Similarly, the Cylinder of Cylinder 2 will use the initial conditions for Cylinder of Cylinder 1.

Check that the remaining ports and cylinder are using the correct settings as follows:

•Set the domain to Port 3 of Cylinder 1 (see Figure 14-18)

•Check that Use data of is set to Port 2 of Cylinder 1 as it is an exhaust port

Figure 14-18 Port 3 of Cylinder 1 check

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