Hydrothermal performance analyses of an isothermal tube with punched twisted tape turbulator (PTT)

Abstract

This study represents a pioneering investigation into the impact of a punched twisted tape turbulator on the hydrothermal parameters of a pipe operating under constant surface temperature conditions. The punched turbulator was specifically designed by incorporating cuts with diverse geometries, including semicircular, square, and triangular shapes, into the basic twisted tape turbulator. To evaluate the performance of the punched twisted tape, a comparative analysis was conducted with both a smooth tube and a tube equipped with a basic turbulator. The criterion for selecting the optimal cut geometry was the thermal enhancement factor. Subsequently, the influence of the cut area on the hydrothermal parameters was thoroughly elucidated. The enhancement factor was again utilized to identify the most optimal area. Based on the comprehensive evaluations, it was observed that the turbulator with a semicircular cut geometry and a diameter of 5 mm exhibited superior thermal performance compared to all other geometries. By employing this specific turbulator design, a remarkable enhancement in heat transfer and pressure drop within the heat exchanger was achieved, offering improvements of up to 1.63 and 3.65 times, respectively, when contrasted with the plain tube. The maximum enhancement factor value recorded during the investigation reached 1.09.

Keywords

• Heat transfer
• Pressure drop
• Punched twisted tape turbulator
• Enhanced turbulator