spiral insert 3d model

A spiral air foil insert made of 1 mm thick aluminum sheet is designed for a 25 mm diameter inner tube of a double pipe heat exchanger. The insert has a width of 18 mm and a total length of 950 mm with a spiral pitch of 100 mm. The insert is helically twisted to create swirl flow and turbulence inside the tube, enhancing the heat transfer rate between the fluids.the insert has spring like structure