Sensitivity analysis of boehmite alumina nanofluid in a novel cylindrical heat sink with hybrid helical-straight minichannels using the taguchi method and statistical analysis

Abstract

In the present study, heat transfer, fluid flow characteristics and entropy generation of boehmite alumina nanofluid in a cylindrical heat sink with hybrid helical-straight minichannels are simulated and examined numerically. Attention is focused to determine the influential design factors and the optimal levels for output parameters. The design factors are selected at four levels including the helix angle of minichannels, the Reynolds number, the helical length ratio, the nanoparticles shape and the volume fraction of nanoparticles. Sensitivity analysis of design factors was carried out using the Taguchi method with L16 orthogonal array and statistical analysis of variance (ANOVA). The Nusselt number (Nu), the Fanning friction factor (f), the total hydrothermal performance factor (JF), the rate of entropy generation (Sgen), and the entropy generation number (Ns), are selected as the output parameters. The obtained results revealed that the helix angle of minichannels and the Reynolds number play a vital role in Nu, JF, and Sgen, with the sum of the contribution ratios of the two factors 82.57%, 68.16%, and 81.97%, respectively. Also, the helix angle of minichannels has a 50.67% contribution in Ns. The optimized model is improved by 94.5%, 37.5%, 84%, 63.4%, and 64.1% for Nu, f, JF, Sgen, and Ns, respectively, compared with the original model. Two optimal combinations for JF and Sgen are acquired as A2B3C1D4E4 and A1B3C4D4E4, respectively. Overall, the hybrid helical-straight minichannel with boehmite alumina nanofluid can be beneficial as a preferred cooling for the cylindrical heat sources.