Analysis of the Effect of Graphene Oxide on Heat Transfer in Pulsating Heat Pipes based on Response Surface Methodology
Response surface methodology(RSM)is an effective tool for evaluating the extent to which multiple independent variables affect processes and outcomes.Based on the RSM method,the heat trans-fer enhancement effect of graphene oxide(GO)nanofluids on pulsating heat pipes(PHP)was experi-mentally studied.The heating power of 20 to 105 W,the liquid filling rate of 25%to 75%and the mass fraction of GO nanofluids of 0%to 0.1%were adjusted to analyze their influence on the heat transfer performance of PHP.Results show that the heat transfer performance of GO/water PHP is affected by the heating power,liquid filling rate and mass fraction of GO nanofluid;heating power Q has the greatest effect,followed by liquid filling rate FR,and mass fraction ω has the least effect;in terms of the influ-ence of the cross term,Q has a strong interaction with FR,which means that it has a significant effect on the thermal resistance;when the interaction between FR and ω is weak,its effect on thermal resistance is small;the interaction between Q and ω has minimal effect on thermal resistance;the predicted optimal operating parameters are as follows,Q is 96.4 W,FR is 67.5%,ω is 0.041%,and the corresponding thermal resistance value Rmin is 0.463 K/W;in conclusion,the application of RSM method can greatly reduce the number of tests,effectively analyze the heat transfer performance and influencing factors of GO/water PHP,and predict the optimal operating conditions.