Numerical investigation on effects of plain, perforated, and dimpled twisted tape inserts in a tube to flow and heat transfer characteristics

Abstract

This research delves into improving heat transfer within tube by incorporating twisted tape inserts numerically comprising seven cases: basic twisted tape, perforated twisted tape with lengths of 25, 50, and 100mm, dimpled twisted tape with lengths of 25, 50, and 100mm. Analyses have been conducted at five different Reynolds numbers (10,000, 12,000, 15,000, 18,000, 20,000) using water as the working fluid. Physical dimensions of the geometry include tube length of 1000mm, inner diameter of 17mm, and outer diameter of 21mm. The twisted tape is also 1000mm long, with width of 17mm and thickness of 1mm. Results are compared to smooth tube in terms of Nusselt number and friction factor. Best improvement was obtained for 25mm dimpled twisted tape with 42%, while improvement for perforated tape was 28.7% and for plain tape 24%. Higher friction factors were obtained at 25mm dimpled tape making these configurations useful for industry despite pressure drop.

Keywords:

• CFD
• dimpled
• heat transfer
• perforated
• performance evaluation criteria
• twisted tape

Disclosure statement

No potential conflict of interest was reported by the author(s).