Numerical study of pool boiling heat transfer on pin-fin surface submerged in dielectric fluid

Abstract

This study employs the Eulerian–Eulerian Rensselaer Polytechnic Institute (RPI) model and performs numerical simulations to investigate pool boiling heat transfer on pin–fin structured surfaces submerged in dielectric fluid FC-72. Utilizing the Eulerian–Eulerian approach, different force, interface, and boiling models are examined using extensive numerical simulations, and suitable model selections are proposed that enhance the heat flux predictions. A two-dimensional polynomial correlation for the bubble waiting time coefficient (C_w) is developed as a function of the area enhancement factor and wall superheating based on available experimental data for rectangle-shaped fins. Further studies validating the model against experimental data excluded from the correlation development demonstrated a maximum error of 7.34% in the heat flux prediction. The RPI model is further utilized for different-shaped pin–fin geometries, such as rectangular, trapezoidal, and hierarchical fins. Performance comparison studies revealed that hierarchical fins consistently achieved the highest heat flux values, indicating their superior heat transfer capacity in comparison with rectangular and trapezoidal fins that have the same number of fins and identical area enhancement factors. The presented model and correlations are expected to offer a strong numerical framework for optimizing thermal management solutions in electronic cooling applications using dielectric fluids.