Comparative analysis of heat transfer performance in film boiling on a superheated vertical cylinder: A detailed CFD study of water-based Al2O3 and Cu nanofluids

Abstract

This study investigates the impact of nanoparticle types on the thermal dynamics of film boiling in water-based nanofluids, specifically focusing on nanofluids containing Al${}_2$O${}_3$ and Cu nanoparticles along a vertical cylinder. The investigation employs the Continuous-Species-Transfer approach and also considers the effects of Brownian motion and thermophoresis. A 2D axisymmetric analysis is performed, evaluating the influence of nanoparticle type—Al${}_2$O${}_3$ and Cu—on the boiling heat transfer efficacy. Through the examination of volume fraction, temperature distributions, nanoparticle concentration, and thermophysical characteristics, the study also examines the Nusselt number. Results show the nanoparticle enrichment at the vapor–liquid interface and the degree of this nanoparticle enrichment influences nanoparticle concentration at the cylinder wall, with higher enrichment at the interface inversely related to wall concentration. While Al${}_2$O${}_3$ nanoparticles show higher concentration at the wall, Cu nanoparticles are more effective in enhancing Nusselt number, particularly in nanofluids with higher nanoparticle concentrations.