# How to apply an outlet velocity profile to another inlet?

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 March 23, 2013, 05:41 How to apply an outlet velocity profile to another inlet? #1 Senior Member   Stuart Join Date: Jul 2009 Location: Portsmouth, England Posts: 735 Rep Power: 25 Hi, I'm first doing a 2D flat plate zero pressure gradient RANS simulation to get the fully developed turbulent boundary-layer velocity profile. I then need to apply the velocity profile to the inlet of a 3D simulation of a wall mounted body. The height of the 2D and 3D fluid domains is the same. Is it possible to take the velocity profile at the 2D domain outlet and assign it the inlet of the 3D domain? The 2D velocity profile at the 3D inlet should be swept in the spanwise directon. I cannot see how to do this or any instructions in the User Guide. If that is not possible then is it possible to define an equation of the boundary-layer velocity profile at the 3D domain inlet? Assuming I can find the correct equation for the velocity profile of a fully developed turbulent boundary-layer on a flat plate. Thanks.

 March 23, 2013, 12:06 #2 Super Moderator     Alex Join Date: Jun 2012 Location: Germany Posts: 3,400 Rep Power: 47 This can be done without much effort. You can write the profile data from the 2D simulation (find it for example in the boundary conditions tab). The same way, you can read the profile to the 3D simulation. The profile should be swept automatically to the third dimension.

 March 23, 2013, 12:39 #3 Senior Member   Stuart Join Date: Jul 2009 Location: Portsmouth, England Posts: 735 Rep Power: 25 Thanks for the replay Alex. Does the quantity and distribution of the mesh nodes needs to be the same on the 2D outlet and the 3D inlet for the data to be transfered?

 March 23, 2013, 15:06 #4 Super Moderator     Alex Join Date: Jun 2012 Location: Germany Posts: 3,400 Rep Power: 47 Not necessarily. there are several interpolation methods available.

 April 10, 2013, 11:19 #5 Senior Member   Stuart Join Date: Jul 2009 Location: Portsmouth, England Posts: 735 Rep Power: 25 Hi, I've seen how to output the 2D outlet profiles and also to load them into the 3D inlet. But how is it possible to copy/extend the 2D profile along the third-dimension? The domain heights of the 2D outlet and 3D inlet are the same so theree is no data extrapolation, only data interpolation due to the different mesh node distributions but the FLUENT User Guide says this is okay. Thanks