Investigation and optimization of heat transfer performance of a spirally corrugated tube using the Taguchi method

A three-dimensional numerical model of a spirally corrugated tube is built in this study using ANSYS FLUENT software. The effects of three geometric parameters (i.e., starts number, corrugation depth, and corrugation spacing) on the heat transfer performance are analyzed using the Taguchi method. Based on the influence of the Reynolds number, the optimal structure yielding the best heat transfer performance is obtained. The streamline patterns show that heat transfer is enhanced by the generation of the secondary flow near the spirally corrugated tube wall. Main-effect analysis and analysis of variance both indicate that the contributions of the corrugation depth and corrugation spacing to heat transfer coefficient account for approximately 90%. The mean Heat transfer coefficient improved by 36.3% when corrugation depth increases from 1 mm to 3 mm. While it decreases by 4.8% when corrugation spacing increases from 9 mm to 13 mm. Results show that a larger corrugation depth and smaller corrugation spacing could generate improved heat transfer performance. In addition, the small difference between predicted signal-noise-ratio and signal-noise-ratio implies that the effects of factor interaction on the results for the optimization process can be ignored. The corresponding optimal parameter combinations for the spirally corrugated tube with four starts, corrugation depth e = 3 mm, corrugation spacing P = 9 mm could enhance the heat transfer by 15.0% and 4.9% for Re = 30,000 and 60,000.