An example of a .xy table file is shown below. Each column of data must have the same number of elements. There must be columns of data identified as 'X', 'Y' (and 'Z' in three-dimensional space).
Y X Z U
0.0 0.0 0.0 0.00000
0.0005 0.0 0.0 0.11408
0.001 0.0 0.0 0.22230
0.002 0.0 0.0 0.42120
0.003 0.0 0.0 0.59670
0.004 0.0 0.0 0.74880
0.005 0.0 0.0 0.87750
... ... ... ...
0.3 0.0 0.0 0.00000
Although .csv is the standard format for exporting table data from STAR-CCM+, .xy is still supported as a legacy format for reading into a simulation.