Influence of the geometrical parameters and particle concentration levels of hybrid nanofluid on the thermal performance of axial grooved heat pipe

Abstract

In the present study, a numerical model is developed to maximize the thermal performance of axial grooved heat pipe (AGHP) working on CeO2 + MWCNT / water based hybrid nanofluid (HNF). The effects of a wide range of volume concentration (0.25%−1.50%) at different operating temperatures (55 ℃−75 ℃) are analyzed to maximize the thermal performance of AGHP. The current numerical work aims at finding the heat transport capacity, Qmax, and total thermal resistance, Rtotal, of AGHP with acceptable accuracy by validating it with the past experimental studies. It has been observed that the highest Qmax is achieved at 1.25% of the volume concentration of HNF for each operating temperature. The novel HNF based AGHP shows an enhancement of 61.27% in the heat transport capacity and a reduction of 30% in the total thermal resistance compared to the water-based AGHP. The study is further extended by incorporating the effects of geometrical parameters on AGHP’s thermal performance. Three geometrical parameters are considered in this study, namely groove height (hg), number of axial grooves (N), and their inclination angle (α). A total of 128 combinations of N, hg, and α have been analyzed to optimize Qmax and Rtotal. The maximum thermal performance of AGHP is achieved at N = 28, hg = 1.3 mm, and α = 76°, where the Qmax = 78.5 W and Rtotal = 0.054 °C/W.