Chapter 17	DIESEL ENGINE: STAR SET-UP IN ES-ICE AND PRO-STAR
	STAR Set-up in es-ice

Figure 17-6 Closed-cycle Star Controls > Boundary Conditions panel for the Cylinder

Next, choose Angelberger as the wall function model and combine all patches for a given boundary type into a single boundary region (see Figure 17-7):

•Select Global settings from the drop-down menu at the top of the panel

•Check that the Wall function model is set to Angelberger

•Click Check regions to check that all regions are valid

•Ensure the consistently toggle button is selected and then click Join regions

Figure 17-7 Closed-cycle Star Controls > Boundary Conditions panel for Global settings

Post setup

In a diesel engine analysis, it is particularly useful to output and plot scatter data of equivalence ratio vs. temperature on a per-cell basis (see Chapter 8, “Post set-up” in the User Guide). The plots are then used to evaluate the fuel-air mixture quality distribution in the cylinder.

In the Post-setup view of the Star Controls panel (see Figure 17-8):

•Select the Phi vs temperature toggle button to output equivalence ratio and temperature data

•Use the data range up/down scroll arrows to increase the number to 4 data ranges

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DIESEL ENGINE: STAR SET-UP IN ES-ICE AND PRO-STAR	Chapter 17
STAR Set-up in es-ice

•Define each data range as follows:

•Data range 1: Set Begin angle to 732, End angle to 736 and Interval to 2

•Data range 2: Set Begin angle to 750, End angle to 752 and Interval to 2

•Data range 3: Set Begin angle to 770, End angle to 772 and Interval to 2

•Data range 4: Set Begin angle to 790, End angle to 792 and Interval to 2

Figure 17-8 Closed-cycle Star Controls > Post-setup panel

Time step control

In problems involving complex spray and combustion models, stability and accuracy considerations dictate that the time step size is suitably adjusted before continuing the analysis past the fuel injection and onset of combustion stages.

In the Time step control view of the Star Controls panel (see Figure 17-9):

•Use the time step up/down scroll arrows to increase the number to 2 time steps

•Set the step size applicability range and magnitude (in terms of crank angle) as follows:

•Time step 1: Set Angle to 680 and Step to 0.05

•Time step 2: Set Angle to 700 and Step to 0.025

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