Response Analysis and Thermal Performance Evaluation of Pulsating Heat Pipe with Surfactant Solution

Appropriate addition of the surfactant cetyltrimethylammonium bromide (CTAB) can significantly reduce solution surface tension and promote boiling heat transfer. In this study, it was applied to a pulsating heat pipe (PHP), and the experimental study was guided using response surface methodology (RSM). The influence of heating power (Q=10-105 W), filling ratio (α=25%-75%), and CTAB concentration (ω=0-0.29%) on the heat transfer performance of PHP was studied. The results show that the proper addition of CTAB (e. g.,ω=0.145%) at a moderate filling ratio (α=50%) can effectively improve the operation of PHP, reduce thermal resistance, and transform temperature fluctuation characteristics at lower powers. In terms of influencing factors, the heating power had the greatest influence, followed by the filling ratio, whereas concentration had the least influence. The interaction between heating power and filling ratio was the most significant, whereas that between the filling ratio and concentration was not significant. The minimum thermal resistance was predicted as approximately 0.32 ℃/W, and a relatively wide optimal operating condition area existed, which makes the overall thermal resistance of PHP relatively small. This is beneficial for the practical application and performance optimization of PHP in engineering.