Numerical Study on Pool Boiling of Hybrid Nanofluids Using RPI Model

Abstract

The performance of deionized (DI) water and hybrid nanofluids for pool boiling from a horizontal copper heater under atmospheric pressure conditions is numerically examined in the current study. The Eulerian–Eulerian scheme is adopted with a Rensselaer Polytechnic Institute (RPI) sub-boiling model to simulate the boiling phenomena and predict the heat and mass transfer in the interior of the pool boiling vessel. This paper attempts to correct the coefficient of the bubble waiting time (BWTC) in the quenching heat flux partition as a proportion of the total heat flux and then correlate this coefficient to the superheat temperature. The pool boiling curve and pool boiling heat transfer coefficient (PBHTC) obtained for the present model are verified against experimental data from the literature and show good agreement. In addition, this work comprehensively discusses the transient analysis of the vapor volume fraction contours, the vapor velocity vectors, and the streamlines of water velocity at different superheat temperatures. Finally, for BWTC, new proposed correlations with high coefficients of determination of 0.999, 0.932, and 0.923 are introduced for DI water and 0.05 vol.% and 0.1 vol.% hybrid nanofluids, respectively.

Keywords

• hybrid nanofluids
• RPI model
• BWTC
• pool boiling
• heat flux
• quenching heat flux