This CFD investigation examines the pressure drop, friction factor, and thermal–hydraulic performance of geometrically modified twisted tape inserts in a circular pipe. Twisted tape inserts are passive heat transfer devices that improve fluid mixing by producing swirl flow, turbulence, and stronger wall-fluid contact. However, such modifications may also increase pressure drop and friction factor, which can raise pumping power. Therefore, this work aims to identify a twisted tape design that provides better heat transfer with acceptable flow resistance. Four geometries were studied: Plain Twisted Tape, Double-Hole Perforated Twisted Tape, Curved-Slot Twisted Tape, and Multi-Hole Perforated Twisted Tape. A 400 mm long pipe with 42 mm inner diameter and 44 mm outer diameter was modeled with a full-length twisted tape insert. The mesh was generated in ANSYS Fluent Meshing with 472,350 cells. Water was used as the working fluid, while the pipe and twisted tape were assigned as aluminum. The standard k-epsilon turbulence model was used for turbulent flow simulation. The Multi-Hole Perforated Twisted Tape showed the highest heat transfer rate of 57.67 W and the best thermal–hydraulic performance value of 1.238. This design is the most suitable among the tested geometries.