I am trying to design a contraction for a wind tunnel and I wish to look at the velocity profile at several x-positions along the contraction. I can not figure out how to plot a profile for a selected x-position. I can only plot the profiles at the boundary conditions I have defined such as the inlet, outlet, etc.

If your geometry is 2d you can try to place isosurfaces from x-coordinates. Otherwise, you can buildline/rake. Enter the coordinate of two vertexes and plot on the line you just create.

create plane if you have a geometry in 3d and you can display contours at this plane

do the following; 1) locate a point/point surface on the location 2) with help of coordinates or surface tool (selecting th epoint through mouse) 2) read the profile on this surface