multiple curves in the iges file
 

I imported the DLR- wing body configuration iges file in icemcfd.
But once i import icemcfd is giving me coplanar curves, i.e two
curves lying in top of each other. It is also very difficult to manually
clean up, as every edge has one collinear edge.
Any suggestions on how to clean up?

Build Topology...
 

Yes, easy (if you know where).

Geometry (tab) => Repair Geometry => Build Diagnostic topology.

Set the tolerance to something bigger than the distance beween the curves you want to remove, but smaller than the mesh size. (maybe 1/10th of the smallest mesh size to 1/2 the mesh size).

This will remove duplicate curves and surfaces, among many other things.

Look in the help for more on what Build Topology does.

Simon