23.7.4 Reporting of Current Positions for Unsteady Tracking

In transient cases, when using unsteady tracking, you may want to obtain a report of the particle trajectory/trajectories showing the current positions of the particles. Selecting Current Positions under Report Type in the Particle Tracks dialog box enables the display of the current positions of the particles.

The procedure for generating files containing current position reports is listed below:

1.   Follow steps 1 and 2 in Section  23.7.1 for displaying trajectories. You may want to track only one particle stream at a time, using the Track Single Particle Stream option.

2.   Select Current Position as the Report Type.

3.   Select File as the Report to option. (The Display button will become the Write... button.)

4.   In the Significant Figures field, enter the number of significant figures to be used in the step-by-step report.

5.   Click the Reporting Variables... button. The Reporting Variables dialog box will appear (Figure  23.7.3), where you can change the variables in the report. The list under Variables in Report contains all variables currently reported. The Remove button removes selected variables from that list. The Default Variables button restores the default list. The list under Particle Variables contains the particle variables that are available for you to select. You can add selections to the report using the Add Variable button. Clicking the Add Color by button adds the Color by variable to the list of Variables in Report, which is the only way to get cell values or customized field functions into the report.

Note that it is possible to select one variable in the Reporting Variables dialog box and a variable from the Color by drop-down list in the Particle Tracks dialog box, however, each variable is reported only once.

6.   Click the Write... button and specify a file name for the current position report file in the resulting Select File dialog box (see Section  2.1.6).

The default current position report lists the position, velocity, diameter, temperature, density, mass and number in parcel of the particle at selected time steps along the trajectory. In addition, the variable you have selected in the Color by list is also included. If you change the reporting variables, only those selected will appear in the report. The particle time is always reported in the first column. It is possible to select one variable in the Reporting Variables dialog box and a variable from the Color by drop-down list in the Particle Tracks dialog box, however, each variable is reported only once.

The output to a file or to the console has the same format as the step-by-step report for steady-state cases.

Time        X-Position  Y-Position  Z-Position  X-Velocity  Y-Velocity  Z-Velocity
 0.000e+00   1.000e-03   3.120e-02   0.000e+00   1.000e+01   5.000e+00   0.000e+00
 1.672e-05   1.168e-03   3.128e-02   0.000e+00   1.010e+01   4.988e+00   0.000e+00
 3.342e-05   1.337e-03   3.137e-02   0.000e+00   1.019e+01   4.977e+00   0.000e+00
 5.010e-05   1.508e-03   3.145e-02   0.000e+00   1.028e+01   4.965e+00   0.000e+00
 6.675e-05   1.680e-03   3.153e-02   0.000e+00   1.038e+01   4.954e+00   0.000e+00
 8.338e-05   1.854e-03   3.161e-02   0.000e+00   1.047e+01   4.942e+00   0.000e+00
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Also listed are the diameter, temperature, density, mass of the particles, number in parcel and the variable selected from the Color by list. (You may need to use the scroll bar to view this information.)

Time	      Diameter	  Temperature    Density      Mass       Number    ColorBy     
9.999e-04   9.352e-05	3.710e+02    6.840e+02   2.929e-10   2.792e+02  4.783e-02 
1.999e-03   7.952e-05	3.710e+02    6.840e+02   1.801e-10   2.792e+02  3.834e-02 
3.000e-03   6.660e-05	3.710e+02    6.840e+02   1.058e-10   2.792e+02  2.989e-02 
4.001e-03   5.425e-05	3.710e+02    6.840e+02   5.719e-11   2.792e+02  3.719e-02 
5.001e-03   4.184e-05	3.710e+02    6.840e+02   2.624e-11   2.792e+02  2.978e-02
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