The TUI command to imprint a surface (please make sure the surface file / mesh is in the same directory) : mesh/surface-mesh/read “file.stl” In the next prompt, enter the units in which the mesh was created. This reads in the stl to the current case file. To imprint the surface, /surface/imprint-surface Enter the Surface zone name, new surface imprint name and the zone name you want to imprint. Note : Fluent automatically creates a surface imprint name containing strings “imprint”.