Comprehensive heat transfer performance analysis of liquid metal based nanofluid laminar flow in circular tube

摘要

Liquid metal based nanofluid is expected to be the ultimate coolant, however, till date a comprehensive heat transfer analysis of this fluid flow is still lacking. The paper presents the comprehensive analysis of heat transfer, entropy generation and performance evaluation of liquid metal nanofluid laminar flow in a circular tube subject to constant wall heat flux, in which the two-phase mixture model is adopted to simulate the nanofluid flow, and three types of nanoparticles (namely Alumina (Al2O3), Diamond (Diam), Carbon nanotubes (CNT)) is considered. The computational results show that, as nanoparticles volume fraction increases, the average heat transfer coefficient of Ga-Diam and Ga-CNT increases, but that of Ga-Al2O3 decreases. The corresponding total entropy generation of Ga-Diam and Ga-CNT decreases, and that of Ga-Al2O3 increases. Particularly, as Re = 1000 and alpha(p) = 0.06 the average Nusselt number of nanofluids Ga-CNT, Ga-Diam and Ga-Al2O3 relative to that of pure liquid metal Ga are increased by 17.3%, 16.1% and - 2.1%, respectively. In general, the liquid metal based nanofluid with high concentration carbon nanotubes nanoparticles is a better choice for heat transfer enhancement, however, from the view point of energy utilization efficiency low concentration nanoparticles is more suitable.