A validated CFD model of plain and serrated fin-tube bundles

Abstract

This work presents a Computational Fluid Dynamics model of helically wound fin tube bundles and demonstrates its predictive capability for thermal-hydraulic performance. A consistent validation against experimental data is given for four different fin tube geometries, two with plain fins and two with serrated fins. Predicted heat transfer and pressure drop data are within, or very close to, the experimental uncertainty, with maximum root mean square errors of 13.8% and 14.4% respectively. The modeled fin temperature distribution is used to evaluate three fin efficiency models, revealing that correction equations can be in significant error for tall plain fins. Three sets of semi-empirical correlations for Nusselt and Euler numbers are also evaluated, showing non-conservative predictions for several of the tested geometries. Results from the study confirm the efficacy of reduced domain modeling, whereby geometric periodicity of the heat exchanger array is exploited to reduce computational cost.