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valve. It is recommended that you then check this spline to make sure the valve shape is correct:
•Enter the following command to select each valve with the cursor in the Geometry window and add it to the current CSet.
CSet, Newset, Type, Cursor
•Adjust the viewpoint to display the valves as shown in Figure 10-6
Figure 10-6 View of valve profiles
•If the profiles are correct, enter the following command and reply “Yes” to the prompt in order to remove the splines:
SClear, All
Creating the Automatic 2D Template
The first step in creating the automatic 2D template is to define the engine operating conditions and characteristics in the General parameters and Events parameters panels.
To set the general parameters:
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In the Select panel, click Create |
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Template |
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In the Create Template panel, click |
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General |
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In the General parameters panel, set |
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Engine type to Diesel and Cylinder radius |
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to 61.5, as shown in the adjacent Figure |
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Check that Base style is set to 4 Valve |
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Click Ok to accept the current settings and |
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then close the panel |
To set the event parameters:
•In the Events parameters panel, set Crank angle start (deg) to 350 and Crank angle stop (deg) to 720
•Set Engine RPM to 2000 and Connecting rod length to 200
•Check that the Piston pin offset is 0 and the Valve lift periodicity (deg) is 720, as shown in the adjacent Figure
•Click Ok
You can now generate the automatic 2D template. This procedure requires setting parameters in the Automatic 2D parameters panel to define the cell count in certain parts of the template. The rest of the template uses a relatively uniform cell size based on these parameters. For more details on this panel’s parameters see Chapter 4, “The Automatic 2D Parameters panel” in the User Guide.
To create the automatic 2D template:
•In the Create Template panel, select the Automatic toggle button as shown in Figure 10-7
•Click the Automatic 2D button
•In the Automatic 2D parameters panel, check that Circumferential cells is set to 72 (see Figure 10-7)
•Click Create 2D
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Figure 10-7 Create Template and Automatic 2D parameters panels
When the calculation is complete, the automatic 2D template appears in the General Workspace window as shown in Figure 10-8.
Figure 10-8 Initial 2D template
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Refining the 2D Template Around the Injector |
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Refining the 2D Template Around the Injector
The automatic 2D template facility allows you to refine the mesh around a circular region with a user-defined mesh size multiplier, point and radius. This can provide higher mesh resolution around important features, such as the fuel injector.
To refine the mesh around the injector:
•In the Automatic 2D parameters panel, set Use source to Yes
•Set the Radius to 7.5. The injector radius is 5, so a value of 7.5 ensures that some cells around the injector are also refined
•Check that X and Y are set to 0 and Mesh size multiplier is set to 0.5. In this case, the injector is located at the centre of the cylinder (i.e. at 0, 0) and halving the mesh size gives sufficient mesh refinement
•Click Create 2D
When the calculation is complete, a refined automatic 2D template appears in the General Workspace window as shown in Figure 10-9.
Figure 10-9 Refined 2D template
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