Chapter 7	STAR SET-UP IN PRO-STAR
	Using the es-ice Panel

Chapter 7 STAR SET-UP in pro-STAR

The following tutorial data files are used in this chapter:

es-ice.PNL
GRID_MOVE.NULL
MAKE_EV.BAT
READ_TMP.BAT			(Created in Chapter 6)
template.bnd
template.cel
template.cpl
template.vrt

Most of the physics set-up is done via the Star Controls panel as described in Chapter 6. The Star Controls > Write data stage generates a pro-STAR panel and a series of input files that simplify the model import into pro-STAR. After importing the model, the remaining pro-STAR tasks are to set the analysis controls and then write data files for the STAR solver.

This chapter describes the analysis set-up procedure using pro-STAR Version 4.20 and covers the following stages:

1.Importing the model into pro-STAR via a special es-ice panel

2.Setting the Analysis Controls to define the solution method and analysis output

3.Writing a geometry and problem file for use by the STAR solver

Using the es-ice Panel

The es-ice panel redefines pro-STAR’s memory allocation, imports the model and defines ‘events’ that describe the piston and valve motion. These actions can be executed by issuing pro-STAR commands, but the es-ice panel simplifies the process by providing a set of special-purpose buttons. This panel was created automatically during the Star Controls > Write data process, as described in Chapter 6 of this volume.

Each region in the flow field that may potentially become separated from other regions due to valve motion is defined as a separate “material”. Different material types are automatically assigned to different regions according to how the valve motion separates them from each other.

•Launch pro-STAR in the usual manner

•In the pro-STAR launch panel, accept star as the default Case Name and click Continue

•From the menu bar, select Panels > es-ice

•In the es-ice panel (see Figure 7-1), click Resize to update the param.prp file using MEMORY commands

•Click Model to read the boundaries, cells, cell couples and vertices of the es-ice model. This button also reads in the initial and boundary conditions and sets some model defaults. A report on the result of this process is written to a file called READ_TMP.OUT.

•Click Events to define the necessary pro-STAR events and put them in a file called star.evn. A report on the result of this process is written to a file called MAKE_EV.OUT.

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STAR SET-UP IN PRO-STAR	Chapter 7
Setting Solution and Output Controls

Figure 7-1 The es-ice panel

Since the last two steps involve many commands, it is difficult to locate and inspect any pro-STAR errors. It is therefore recommended that you search the two report files for any warning or error messages. For example, the following Linux command can be used in your current working directory:

egrep ‘WARNING|ERROR’ *.OUT

Note that in this tutorial some non-critical warnings are reported in the files but these can be safely ignored.

Setting Solution and Output Controls

You now need to set various analysis and output control parameters via the pro-STAR Model Guide.

For a trimmed model, the recommended pressure correction under-relaxation factor is 0.5:

•In the Analysis Controls > Solution Method panel (see Figure 7-2), set Under Relaxation for Pressure Correction to 0.5

•Click Apply

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Chapter 7	STAR SET-UP IN PRO-STAR
	Setting Solution and Output Controls

Figure 7-2 Analysis Controls > Solution Method settings

Set the analysis output controls. These determine the data available for post-processing in pro-STAR, after the analysis is complete.

•Open the Analysis Controls > Analysis Output panel

•In the Post tab (shown to the left of Figure 7-3), set the Output Frequency to

10 and the Backup Frequency to 300

•Click Apply. These settings instruct STAR to write data to the star.ccmp file once every 10 time steps and to create a back-up file every 300 time steps

•Select the Transient tab (shown to the right of Figure 7-3)

•Set the Starting at time (degCA) to 320 degrees crank angle

•Set the Output interval (degCA) to 5 degrees crank angle to define the frequency of writing solution data to the transient post file

•Deselect the Wall check-box

•Select C8H18 and then select the Post check-box to write the fuel solution data to the transient post file

•In the same way, select solution data output for density and temperature

•Click Apply

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STAR SET-UP IN PRO-STAR	Chapter 7
File Writing

Figure 7-3 Analysis Controls > Analysis Output settings

File Writing

Finally, follow the usual pro-STAR procedure for writing the geometry and problem files and for saving the model file, as shown in Figure 7-4.

•From the menu bar, select File > Save Geometry

•In the Save Geometry File panel, set the Geometry Scale Factor to 0.001 to convert the problem geometry from metres to millimetres

•Click Apply and then Close

•From the menu bar, select File > Save Problem

•In the Save Problem File panel, click Save to write the star.prob file

•From the menu bar, select File > Quit

•In the Quit pro-STAR panel, click Save & Quit to save the model data and quit the pro-STAR session

Figure 7-4 File writing and exit from pro-STAR

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