Page History

...

You can see that the axial velocity at the centerline (U_center) decreases sharply after the inlet, and that it will asymptotically approach 0m/s far from the jet. However, the half-width (Y distance at which U=U_center/2) increases along X as the spray expands into the environment. 

To obtain this distancethe half width, export the X coordinate, Y coordinate, and Axial Velocity by going to File-Export to CFD Post (described at the bottom of Turbulent Jet - Turbulent Setup and Solution). Alternately, go to File-Export-Solution Data. Select 'X-coordinate', 'Y-coordinate', and 'Axial Velocity' as values to export. Export them along the centerline, and various X locations (like X=10D) as either an Ascii file to copy into Excel, or as a CFD-Post file. Alternately, use Matlab use a Matlab script and this function to read in ASCII files at the specified X locations.

Plotting Using the Matlab script and plotting Y-coordinate approximate locations at which U=U_center/2 - determined by examining the values read in to Matlab - gives the half width variation:

...