Praneeth
Ansys Employee

Hi Siddharth,

Thank you for reaching out to the Ansys learning forum.

Please create a new relative coordinate system at the center of the circular cross-section of the cylinder. Then duplicate around the axis which is along the cylinder length. Kindly check "Creating an Offset Relative CS" and "Duplicating Objects Around an Axis" sections of the HFSS help document accessible under the Help menu.
Best regards,
Praneeth.