Modeling and optimizing perforated twisted tape for heat transfer enhancement

Abstract

Previous studies on twisted tapes based on empirical design may overlook some structures having exceptional performance. To further develop the design flexibility, we propose a parametric modeling method for perforated twisted tapes (PTTs) in conjunction with multi-objective optimization to achieve heat transfer enhancement within the flow channel. This method considers the influence of structures on hydrothermal performance more thoroughly, and accelerates the development process. The control coefficients in the mathematical descriptions of the geometric characteristics expressed by Bernstein–Bézier functions were specified as the design variables. Two types of PTTs, full-width and half-width, were presented based on the variable ranges of width optimization. In the optimization, the observed objectives were the average temperature, root mean square temperature, and friction factor. A three-dimensional computational fluid dynamics model was employed to analyze the heat transfer and flow behaviors under three friction factor weight coefficients (0.1, 0.3, and 0.5) and was validated against experimental data. The numerical results showed that the maximum decrease in the average temperature and root mean square temperature of the heat source could attain 18.58 K (5.46%) and 2.92 K (72.64%), respectively. The friction factor was reduced by a maximum of 3.59 (57.35%) at the weight coefficient of 0.5 compared to 0.1. Furthermore, according to the performance evaluation criterion (PEC), the half-width PTTs generate less flow resistance and exhibit superior overall performance. The proposed method elaborates on the potential design space and provides a framework for the creation of efficient convective heat transfer devices.